7th GRADE SCIENCE QUESTION PLEASE ANSWER AS FAST AS YOU CAN I NEED IT (it can be 1 day late is fine... Ok I'll give you today like this minute and you can answer it when it is posted about 1-2 days but if you can answer it now that will be great)!!!

Question #1: State the role of a nucleus in a cell.

The bond that exists between two oxygen atoms to make the O2 molecule is described as two covalent bonds and two lone pairs of electrons are present on each individual oxygen atom.

A double bond in chemistry is a covalent bond between two atoms that involves four bonding electrons, rather than two as in a single bond.

In the oxygen molecule, O2, the oxygen atoms that make up the molecule are bonded together by sharing two pairs of electrons. Each oxygen atom has 6 valence electrons, if they share two of their valence electrons with each other, they each have 8 valence electrons.

In this way, the so-called octet rule is fulfilled, where atoms gain, lose or share electrons with other atoms to have 8 valence electrons and thus acquire a noble gas configuration.

The atom is the smallest part of the composition of matter, it is indivisible and is composed of a nucleus that has protons and neutrons, and around the nucleus there are the electrons.

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Answer:

the nuclear envelope disappears

Explanation:

Answer:

In the first stage of cell division, before metaphase, during which the chromosomes become visible as paired chromatids and the nuclear envelope disappears.

Explanation:

The TDS (Total Dissolved Solids) can be approximated by multiplying the ppm (parts per million) by a conversion factor of 0.5.

TDS = 450 ppm x 0.5 = 225 mg/L (or ppm)

Answer:

Depending on the context, an independent variable is sometimes called a "predictor variable", regressor, covariate, "manipulated variable", "explanatory variable", exposure variable (see reliability theory), "risk factor" (see medical statistics), "feature" (in machine learning and pattern recognition)

Explanation:

38 grams of NaCl can dissolve in 100 grams of H2O at 70oC, while 130 grams of CaCl2 can dissolve in 200 ml of H2O at 10oC. Solubility is defined as the amount of solute that can be dissolved in a given amount of solvent at a specific temperature and pressure.

As a result, when calculating solubility, it is important to consider the temperature and amount of solvent used.NaCl is the solute, while H2O is the solvent, in the first scenario. The question asks for the quantity of NaCl that can dissolve in 100 g of H2O at 70oC. The solubility of NaCl in water varies with temperature.

As the temperature increases, the solubility of NaCl in water also increases, allowing more NaCl to dissolve in the same amount of water.At 70oC, the solubility of NaCl in H2O is 38 g/100g of water.

As a result, 38 grams of NaCl can dissolve in 100 grams of H2O at 70oC.In the second scenario, CaCl2 is the solute, and 200 ml of H2O is the solvent. At 10oC, the solubility of CaCl2 in H2O is 74.5 g/100 ml.

As a result, the maximum quantity of CaCl2 that can dissolve in 200 ml of H2O at 10oC is 2 x 74.5 g, which is 149 grams.

However, the question asks for the maximum amount of CaCl2 that can dissolve in 200 ml of H2O at 10oC, which is 130 grams. As a result, this quantity is lower than the maximum solubility of CaCl2 in H2O at 10oC, which is 149 grams. Therefore, 130 grams of CaCl2 can dissolve in 200 ml of H2O at 10oC.

To summarise, 38 grams of NaCl can dissolve in 100 grams of H2O at 70oC, while 130 grams of CaCl2 can dissolve in 200 ml of H2O at 10oC. The quantity of solute that can dissolve in a given amount of solvent is defined as solubility, which varies with temperature. As the temperature rises, the solubility of most substances in water increases, allowing more of them to dissolve in the same amount of water.

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use a strong base to neutralize, like NaOH, KOH, etc

Based on the data and calculations obtained, it can be concluded that the hypothesis stating, "If the density of the object is 19.32 g/ml, then the object is gold" is not supported.

To support this conclusion, the data and calculations regarding the density of the object should be analyzed. If the calculated density of the object differs significantly from the expected value of 19.32 g/ml, it indicates that the object is not gold.

The accuracy and precision of the data can be assessed by comparing the calculated density with the expected density value. If the calculated density is close to the expected value, it suggests high accuracy. Additionally, if multiple measurements of density yield consistent results, it indicates high precision.

Further experimentation could involve additional tests to determine the identity of the object. These tests could include assessing other physical or chemical properties such as melting point, electrical conductivity, or reactivity with certain substances.

Possible sources of error in the experiment could include instrumental errors in measuring the mass or volume of the object, contamination of the object, or inaccuracies in the known density of gold used for comparison. These factors could contribute to deviations between the calculated and expected densities.

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For the complex [Co(CO)5]x, the unknown charge (z) would be +1 based on the application of the 18 electron rule.

To find the charge (z) of the complex [Co(CO)5]x using the 18 electron rule, we can follow the steps below:

Identify the metal: In this case, the metal is cobalt (Co).

Determine the number of valence electrons of the metal: Cobalt is a transition metal with atomic number 27. In its neutral state, it has 27 electrons. However, in a complex, cobalt typically contributes all of its valence electrons to bonding, which is 9 electrons (2 from the 4s orbital and 7 from the 3d orbital).

Calculate the total number of electrons contributed by ligands: The ligand in this case is carbon monoxide (CO), which is a strong-field ligand. Each CO ligand contributes 2 electrons (one from the carbon lone pair and one from the oxygen lone pair) for a total of 5 ligands × 2 electrons/ligand = 10 electrons.

Add the valence electrons of the metal and the ligands: Cobalt contributes 9 electrons, and the CO ligands contribute 10 electrons, giving a total of 9 + 10 = 19 electrons.

Apply the 18 electron rule: According to the 18 electron rule, most stable transition metal complexes have 18 valence electrons. However, there can be variations depending on the ligands and the metal's oxidation state.

Determine the charge (z): Since the complex [Co(CO)5]x has 19 valence electrons, which is more than the expected 18 electrons, it suggests that the complex has a positive charge to balance the extra electron(s). Therefore, the charge (z) of the complex would be +1.

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The standard enthalpy of formation (∆Hf°) is the enthalpy change when one mole of a compound is formed from its constituent elements in their standard states.

Enthalpy is a fundamental concept in thermodynamics that measures the total heat content of a system at constant pressure. It is denoted by the symbol H and is defined as the sum of the internal energy (U) of a system and the product of the pressure (P) and volume (V) of the system.

Enthalpy can be thought of as a measure of the energy stored within a system, including both the internal energy and the work done by or on the system. It is particularly useful in studying chemical reactions and phase transitions, where it helps us understand the heat flow and energy changes involved. In chemical reactions, the enthalpy change (∆H) provides insights into the heat released or absorbed during the reaction.

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Taking into account the reaction stoichiometry, 135.38 grams of CO₂ is produced when 40000 g of C₂H₂ burns completely.

In first place, the balanced reaction is:

2 C₂H₂ + 5 O₂  → 4 CO₂ + 2 H₂O

By reaction stoichiometry, the following amounts of moles of each compound participate in the reaction:

The molar mass of the compounds is:

By reaction stoichiometry, the following mass quantities of each compound participate in the reaction:

The following rule of three can be applied: if by reaction stoichiometry 52 grams of C₂H₂ form 176 grams of CO₂, 40000 grams of C₂H₂ form how much mass of CO₂?

mass of CO₂= (40000 grams of C₂H₂ ×176 grams of CO₂)÷52 grams of C₂H₂

mass of CO₂= 135.38 grams

Finally, 135.38 grams of CO₂ is formed.

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The wavelength of the photons supplied to the pool can be calculated using the formula E = hc/λ, where E is the energy, h is Planck's constant, c is the speed of light, and λ is the wavelength.

First, let's calculate the energy supplied to the pool. The energy required to raise the temperature of 1 mole of water by 1°C is given as 4.18 J/g. Since we have 26.0 moles of photons, we need to multiply the energy per mole by the number of moles: 4.18 J/g * 26.0 moles = 108.68 J.

We know that E is 108.68 J, h is 6.63 x 10^-34 Js (Planck's constant), and c is approximately 3.00 x 10^8 m/s (speed of light). Rearranging the formula, we have λ = hc/E. Plugging in the values, we get λ = (6.63 x 10^-34 J•s * 3.00 x 10^8 m/s) / 108.68 J. After performing the calculation, we find that the wavelength of the photons is approximately 1.83 x 10^-6 meters. To convert meters to nanometers, we multiply by 10^9: 1.83 x 10^-6 meters * 10^9 = 1830 nm. Therefore, the wavelength of the photons supplied to the pool is approximately 1830 nm.

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The wavelength of the photons is approximately 1000 nm

To find the wavelength of the photons, we can use the formula:

Energy = Planck's constant * speed of light / wavelength

First, let's calculate the energy supplied to the pool:

Energy = 4.18 J/g * 26.0 moles * (18 g/mole) * 1°C
Energy = 1979.28 J

Next, we can use the energy equation to find the wavelength:

1979.28 J = Planck's constant * speed of light / wavelength

The Planck's constant is approximately 6.626 x \(10^{-34}\) J·s, and the speed of light is approximately 3 x \(10^{8}\) m/s.

Wavelength = (Planck's constant * speed of light) / Energy
Wavelength = (6.626 x \(10^{-34}\) J·s * 3 x \(10^{-8}\) m/s) / 1979.28 J

Wavelength ≈ \(10^{-6}\) m

Finally, we can convert the wavelength to nanometers:

Wavelength in nm = (\(10^{-6}\) m) * (\(10^{9}\) nm/m)
Wavelength in nm ≈ 1000 nm

Therefore, the wavelength of the photons is approximately 1000 nm.

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The grams of oxygen present in a sample of this compound that contains 56.00 grams of S = 41.9g of oxygen.

The compound contains the following:

Sulphur = 57.20%

Oxygen = 100 - 57.20 = 42.80%

If 57.20% of the sample contains 56g of Sulphur, then 42.80% of the sample will contain X.

Make X the subject of formula,

X = 42.8 × 56/57.20

X= 1712/57.20

X= 41.9g of oxygen

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The predominant form of CH3CH2NH3 at pH = 14 will be the ionized form.

This is because at high pH, the solution is basic, and there are excess hydroxide ions. The hydroxide ions remove a proton from the ammonium ion, forming ammonia and water. The chemical equation for this reaction is as follows:CH3CH2NH3+ OH- → CH3CH2NH2 + H2O

The predominant form of CH3CH2NH3 at pH = 14 is CH3CH2NH2. This is the ionized form of the compound, which has lost a proton to become an amine. The structure of the predominant form of CH3CH2NH3 at pH = 14 is shown below:CH3CH2NH2

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Answer:

C

Explanation:

Noon is the peak amount of sun shining. Therefore the plant will be carrying out a lot of photosynthesis using the light. Cellular respiration happens regularly as well

At midday, what is happening in the leaf of a plant would be photosynthesis and cellular respiration. The correct option would, therefore, be C.

Photosynthesis has two reactions:

The light dependent reaction is rate determining step of photosynthesis. Hence, photosynthesis proceeds at normal rate during the day.

Cellular respiration, on the other hand, takes place with or without light.

Hence, at 12 pm, Noon, both photosynthesis and cellular respiration will be taking place simultaneously in the leaf of plants.

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Answer: D. They turn red litmus paper blue and taste bitter.

Explanation:

Acids are those substances which either donates hydrogen ions when dissolved in water.  They have pH ranging from 1 to 6.9. They are sour in taste. They dissolve metals to give hydrogen gas. They turn blue litmus red.

Bases are those substances which either donates hydroxide ions when dissolved in water or donates a pair of electrons.  They have pH ranging from 7.1 to 14. They are bitter in taste. They are slippery in nature. They turn red litmus blue.

Answer:

1: exothermic

2:hydrated iron (III) oxide

3:reactants

4:precipitate

5: hydrogen gas

Answer:1.exothermic

2.hydrated iron (III) oxide

3.reactants

4.precipitate

5. hydrogen gas

Answer:

69

Explanation:

I thought that I answer is correct

Answer:

The answer is 69

Explanation:

Because if you add one its 66, and so on, hope this helps! but if you add five it will be 69, if you need help with easy equations let me know

While there are several derived mammalian characteristics that define this group of animals, there are also some traits that are not considered unique to mammals. Egg-laying and the lack of a diaphragm in some mammals are examples of traits that are not derived mammalian characteristics.

Derived mammalian characteristics are those traits that distinguish mammals from other animal groups. Some of the derived mammalian characteristics include the presence of mammary glands, hair, three middle ear bones, and a neocortex. These traits are unique to mammals and have been developed throughout evolution to help them survive in their environments. However, there are some traits that are not considered derived mammalian characteristics.
One of the traits that is not considered a derived mammalian characteristic is egg-laying. While most mammals give birth to live young, there are some mammals such as the platypus and echidna that lay eggs. This trait is not unique to mammals and is also seen in other animal groups such as reptiles and birds.
Another trait that is not considered a derived mammalian characteristic is the lack of a diaphragm in some mammals. While most mammals have a muscular sheet called the diaphragm that separates the thoracic and abdominal cavities and aids in breathing, some mammals such as sloths and armadillos lack a fully developed diaphragm.
In conclusion, while there are several derived mammalian characteristics that define this group of animals, there are also some traits that are not considered unique to mammals. Egg-laying and the lack of a diaphragm in some mammals are examples of traits that are not derived mammalian characteristics.

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The new volume of the balloon should be approximately 716.92 cm^3.

To find the new volume of the balloon, we can use the ideal gas law formula:

PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.

Since the pressure is constant,

we can rewrite the formula as V1/T1 = V2/T2, where V1 is the initial volume, T1 is the initial temperature, V2 is the new volume we want to find, and T2 is the new temperature.

Given:
V1 = 456 cm^3
T1 = 255 K
T2 = 400 K

We can rearrange the formula to solve for V2:
V2 = V1 * (T2 / T1)

Substituting the given values, we have:
V2 = 456 cm^3 * (400 K / 255 K)

Calculating this expression:
V2 ≈ 456 cm^3 * 1.57

Therefore, the new volume of the balloon should be approximately 716.92 cm^3.

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To contain five electrons with three of them unpaired, we need five degenerate orbitals.

Orbitals within the same energy level in an atom or molecule that have the same energy are called degenerate orbitals. This implies that electrons in these orbitals have the same amount of energy and are therefore indistinguishable from each other.

If there are multiple orbitals with the same energy level, then they are said to be degenerate orbitals.

This is because each degenerate orbital can hold a maximum of two electrons with opposite spins. Since three of the five electrons need to be unpaired, we need three separate degenerate orbitals to hold these unpaired electrons. The remaining two electrons can be paired in the other two degenerate orbitals.

Therefore, we need five degenerate orbitals in total to contain the five electrons with three of them unpaired.

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The order of reactivity towards nucleophilic acyl substitution for the given carbonyl-containing compounds is:

Most reactive: 3-methylpentanoyl chloride > benzoic anhydride > propionamide > butyl acetate: Least reactive.

The reactivity of carbonyl-containing compounds towards nucleophilic acyl substitution is determined by several factors such as the nature of the leaving group, nature of the nucleophile, and the stability of the intermediate.

3-methylpentanoyl chloride is the most reactive among the given compounds because it has a highly reactive acyl halide group as the leaving group, which can be easily displaced by a nucleophile. The next most reactive compound is benzoic anhydride, which has two carbonyl groups and its intermediate is stabilized by resonance. Propionamide has a less reactive amide group as the leaving group, making it less reactive than the previous two compounds. Butyl acetate has a stable ester group, which makes it the least reactive amongst the given compounds.

The order of reactivity towards nucleophilic acyl substitution for the given carbonyl-containing compounds is 3-methylpentanoyl chloride > benzoic anhydride > propionamide > butyl acetate, with 3-methylpentanoyl chloride being the most reactive and butyl acetate being the least reactive.

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Answer:Substances combine and form a new product because of chemical reactions. During a chemical reaction, the atoms of the reactants rearrange themselves to form new molecules with different properties. For example, when hydrogen gas (H2) reacts with chlorine gas (Cl2), they combine to form hydrogen chloride gas (HCl), which is a new product. The chemical reaction that occurs is:

H2 + Cl2 → 2HCl

In this reaction, the hydrogen and chlorine molecules break apart and then recombine to form hydrogen chloride. The properties of hydrogen chloride, such as its boiling point, melting point, and reactivity, are different from those of hydrogen and chlorine. This is because hydrogen chloride has a different chemical structure and different chemical properties than hydrogen and chlorine.

Chemical reactions occur because of the way atoms interact with each other. Atoms are always trying to achieve a more stable arrangement of electrons in their outermost energy level. When atoms combine to form new molecules, they can achieve a more stable electron configuration, which is energetically favorable. This is why chemical reactions occur and why substances combine to form new products.

The two major differences of terrestrial planets are:

A terrestrial planet, or telluric planet, or solid planet, or rocky planet, is  described as a planet that is composed primarily of silicate rocks or metals.

Terrestrial planets are covered with solid surfaces, while the Jovian planets usually  have gaseous surfaces.

Mercury, Venus, Earth, and Mars are examples of  the terrestrial planets, while the Jovian planets are Jupiter, Saturn, Uranus, and Neptune.

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The student's claim of 4.64 × 10^24 molecules is incorrect, and the correct number of molecules of ammonium acetate used in the reaction is 6.022 × 10^22 molecules.

The mistake the student made is assuming that the molar mass of ammonium acetate directly corresponds to the number of molecules. However, the molar mass of a substance represents the mass of one mole of that substance, not the number of molecules.

To determine the correct number of molecules of ammonium acetate used in the reaction, we need to use Avogadro's number, which relates the number of particles (atoms, molecules, etc.) in one mole of a substance.

Avogadro's number is approximately 6.022 × 10^23 particles/mol. Given that the student used 0.100 mol of ammonium acetate, we can calculate the correct number of molecules by multiplying the number of moles by Avogadro's number:

Number of molecules = (0.100 mol) × (6.022 × 10^23 molecules/mol)

Performing the calculation, we find that the correct number of molecules of ammonium acetate used in the reaction is 6.022 × 10^22 molecules.

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Answer:

HCl is a polar covalent compound, because of electronegativity difference between Cl(3.5) and hydrogen (2). Hence in this way, the bond between HCl breaks and they formed ions in the polar solvent like water .

The option that has little bearing on whether profitable opportunity exists is option c) How many companies in the industry have expanded their plant capacity since Year 10 because it is not detailed enough.

Decision making is known to be a term that connote the method or act that is based on making the right and best decision among the numbers of alternative available.

Note that  It includes the act of classifying and knowing the best on the use of preference, belief, and others.

Therefore, the option that has little bearing on whether profitable opportunity exists is option c) How many companies in the industry have expanded their plant capacity since Year 10 because it is not detailed enough.

See full question below

Which one of the following has little bearing on whether profitable opportunity exists to build additional plant capacity in the upcoming decision round?

a) Whether data in the most recent FIR indicates that unsold inventories of branded footwear were so disturbingly high that many of these unsold pairs were cleared from company inventories at money-losing prices.

b) Whether the most recent year's FIR shows that ample production capacity already exists to supply the combined demand for branded footwear and private-label footwear three years from now.

c) How many companies in the industry have expanded their plant capacity since Year 10.

d) How potential global supply of footwear in the upcoming year compares with expected global demand

e) Whether the branded pairs available for sale in the most recent year (as reported in FIR)

exceeded global branded demand and, if so, by how much.

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Answer:

\(\tt{ \green{P} \orange{s} \red{y} \blue{x} \pink{c} \purple{h} \green{i} e}\)

Highest lattice energy present in MgF₂.

Ionic compounds having following properties has highest lattice energy.

(i) Ions having small radii

(ii) Compound having high charge

KCl, NaF and LiF all are +1 and -1 charges respectively

But in SrF₂, MgF₂ and CaCl₂  , each cation is dipositive

But size order of cations is:

Mg < Ca< Sr

Thus, Answer is MgF₂.

In chemistry, the lattice energy is the energy exchange upon formation of one mole of a crystalline ionic compound from its constituent ions, which can be assumed to initially be within the gaseous kingdom. It's far a measure of the cohesive forces that bind ionic solids.

Lattice energy may be described because the energy required to transform one mole of an ionic stable into gaseous ionic parts. Alternatively, it may be described as the power that ought to be provided to one mole of an ionic crystal with a purpose to separate it into gaseous ions in a vacuum thru an endothermic system.

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A reaction to be spontaneous,overall cell potential must be positive.

(A)The metabolite which would spontaneously reduce oxaloacetate (OAA) is:

alpha-ketoglutarate

(B)The two half cell reactions are as follows:

Reduction half reaction:

Oxaloacetate + 2 H+ + 2 e- --> malate

Oxidation half reaction:

alpha-ketoglutarate --> Succinate + CO2 + 2 H+ + 2 e-

Overall resulting balanced reaction for the reduction of OAA :

Oxaloacetate +alpha-ketoglutarate --> malate + Succinate + CO2

(C)the standard reduction potential for the reaction chosen in (B):

+0.67-0.17 = +0.50 V

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