Which elements did the Curies discover?​

Answer:

cells are a basic unit of structure and function all things

Answer:

Lake pontchartrain

Explanation:

Answer:

313.6 L

Explanation:

use mole/mole ratio to find moles of CO2 (=14)

multiply by 22.4

=313.6 L

The pOH of the 0.001 M NaOH solution is approximately 3.

To determine the pOH of a solution, we need to know the concentration of hydroxide ions (OH-) in the solution.

In the case of a 0.001 M NaOH solution, we can assume that all of the NaOH dissociates completely in water to form Na+ and OH- ions. Therefore, the concentration of hydroxide ions in the solution is also 0.001 M.

The pOH is calculated using the equation:

pOH = -log[OH-]

Substituting the concentration of hydroxide ions, we have:

pOH = -log(0.001)

Using a calculator, we can evaluate the logarithm:

pOH ≈ 3

Therefore, the pOH of the 0.001 M NaOH solution is approximately 3.

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There are approximately 6.022 × 10^23 atoms in 12 grams of Carbon-12 (12C).

The number of atoms in a given amount of a substance can be calculated using Avogadro's number, which represents the number of atoms or molecules in one mole of a substance. Avogadro's number is approximately 6.022 × 10^23.

Carbon-12 is a specific isotope of carbon, with an atomic mass of 12 atomic mass units (amu). One mole of Carbon-12 has a mass of 12 grams. Since one mole of any substance contains Avogadro's number of particles, in the case of Carbon-12, it contains 6.022 × 10^23 atoms.

Therefore, if we have 12 grams of Carbon-12, which is equal to one mole, we can conclude that there are approximately 6.022 × 10^23 atoms in this amount of Carbon-12.

In summary, 12 grams of Carbon-12 contains approximately 6.022 × 10^23 atoms. Avogadro's number allows us to relate the mass of a substance to the number of atoms or molecules it contains, providing a fundamental concept in chemistry and enabling us to quantify and understand the microscopic world of atoms and molecules.

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Answer:

Explanation:

I would sayy....C The hyphae absorb nutrition and detect when conditions are right to sprout a mushroom above ground.

Um I hope I helped bro :P

(-W-) but where's da cOokIeS??..........................Lol jkkk

Answer:

D THE SPROUTEEDMUSHROOM

Explanation:

Mole measure the number of elementary entities of a given substance that are present in a given sample. Therefore, 2.78g  is the mass of HCl.

The SI unit of amount of substance in chemistry is mole. The mole is used to measure the quantity or amount of substance. We know one mole of any element contains 6.022×10²³ atoms which is also called Avogadro number.

Mathematically,

Molarity= number of moles of solute/volume of solution in litre

Where,

moles= given weight /by molecular weight

         = w/ 36.46

Substituting values in equation 1

0.612=(w/36.46)/( 125/1000)

w=0.80g

Therefore, 2.78g is the mass of HCl.

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Answer:

Element

Explanation:

Iron is an element

The compound that acts as the precipitate in this reaction is Pbl₂, or lead(II) iodide.

In the given reaction equation:

KI + Pb(NO3)2 → KNO3 + Pbl₂

The precipitate formed is Pbl₂, which is lead(II) iodide. In the reaction, potassium iodide (KI) reacts with lead(II) nitrate (Pb(NO3)2) to form potassium nitrate (KNO3) and lead(II) iodide (Pbl₂).

Lead(II) iodide is insoluble in water, as mentioned in the statement. When the two chemicals are mixed, lead(II) iodide is formed as a solid precipitate, which appears as a golden substance, as described.

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Answer:

Option A. the hydroxyl group (-OH)

Explanation:

Ethanol, CH₃CH₂OH belongs to the class of organic compound called alkanol.

They have general formula as R–OH

Where

R => is an alkyl group

OH => is the hydroxyl group

The hydroxyl group (OH) is the functional group of the alkanol (alcohol)

Answer:

the hydroxyl group (—OH)

Explanation:

gradpoint

Answer

pH = 8.12

Explanation

pH = -log [H+]

pH = -log [7.60 x 10^-9 M]

pH = 8.12

The percent by mass of nitrogen in ammonia (NH3) is approximately 82.15%

Calculating the mass of nitrogen to the total mass of the compound and then expressing the result as a percentage will allow us to determine the percent by mass of nitrogen in NH3 (ammonia).

Ammonia's molecular structure, NH3, indicates that it is made up of one nitrogen atom (N) and three hydrogen atoms (H). We must take both the molar masses of nitrogen and ammonia into account when calculating the percent by mass of nitrogen.

Nitrogen's (N) molar mass is roughly 14.01 g/mol. The molar masses of nitrogen and hydrogen are added to determine the molar mass of ammonia (NH3). Since hydrogen's molar mass is around 1.01 g/mol, ammonia's molar mass is:

(3 mol H 1.01 g/mol) + (1 mol N 14.01 g/mol) = 17.03 g/mol = NH3.

Now, we can use the following formula to get the nitrogen content of ammonia in percent by mass:

(Mass of nitrogen / Mass of ammonia) / 100% is the percentage of nitrogen by mass.

Ammonia weighs 17.03 g/mol and contains 14.01 g/mol of nitrogen by mass. By entering these values, we obtain:

(14.01 g/mol / 17.03 g/mol) 100% 82.15 % of nitrogen by mass

Ammonia (NH3) has a nitrogen content that is roughly 82.15 percent by mass.

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The mass of the asteroid is C. 1.2 x \(10^{12}\) Kg

To find the mass of the other asteroid, we can rearrange the equation for the gravitational force between two objects:

F = (G * m1 * m2) / \(r^{2}\)

where F is the force of gravity, G is the gravitational constant, m1 and m2 are the masses of the two asteroids, and r is the distance between them.

Given that the distance between the asteroids is 75000 m, the force of gravity between them is 1.14 N, and one asteroid has a mass of 8 x \(10^{7}\) kg, we can substitute these values into the equation and solve for the mass of the other asteroid (m2):

1.14 N = (6.67430 × \(10^{-11}\) N \(m^{2}\)/\(Kg^{2}\) * 8 x \(10^{7}\) kg * \(m2\)) / \((75000 m)^{2}\)

Simplifying and solving the equation, we find that the mass of the other asteroid (m2) is approximately 1.2 x \(10^{12}\) kg. Therefore, Option C is correct.

The question was incomplete. find the full content below:

Two asteroids are 75000 m apart one has a mass of 8 x \(10^{7}\) kg if the force of gravity between them is 1.14 what is the mass of the asteroid

A. 3.4 x \(10^{11}\) kg

B. 8.3 x \(10^{12}\) kg

C. 1.2 x \(10^{12}\) kg

D. 1.2 x \(10^{10}\) kg

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Answer:

its atomic number

Explanation:

which is defined as the number of units of positive charge (protons) in the nucleus. For example, if an atom has a Z of 6, it is carbon, while a Z of 92 corresponds to uranium.

The connection between increasing carbon dioxide and increasing temperature is: carbon dioxide absorbs heat from the sun and traps it in earth's atmosphere. Since the heat cannot escape, it causes the earth's temperature to increase which is the first option.

When carbon dioxide (CO₂) and other greenhouse gases are present in the atmosphere, they act as a natural blanket, allowing sunlight (solar radiation) to pass through and reach the Earth's surface. Some of this solar radiation is absorbed by the Earth's surface, while the rest is reflected back towards space as heat (infrared radiation). However, greenhouse gases like carbon dioxide have the property of absorbing and re-emitting infrared radiation.

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Answer:

Explanation:

Molar weight of HCl is 36.46g/mole

The reaction requires 0.73 g of HCl so it requires

0.73/36.46 = 0.02 mole of HCl

Molarity of HCl is 4.0M = 4mole/liter

0.02/4 = 0.005L = 5mL

5 mL of HCl solution should be used.

Answer:

They increase from left to right and top to bottom.

Answer:

They increase from left to right and top to bottom.

Answer:

Na and Cl option d.

Explanation:

Ionic bond commonly occurs between a metal and non metal on combining to produce a compound.

In that case, the most appropriate choice would be to go with

option d - Na and Cl.

They combine to form common salt or NaCl.

Na ( sodium) is a metal while Cl (chlorine) is a non metal.

About 2.5% of Strontium-90 would remain in the soil at the Trinity Site.

Since the half-life of Strontium-90 is 28.8 years, we can use the formula for radioactive decay to calculate the percentage of Strontium-90 that would remain in the soil after 68 years:

Percentage remaining = (1/2)^(68/28.8) x 100

Solving this equation, we get:

Percentage remaining = 2.5%

This means that after 68 years, only 2.5% of the original amount of Strontium-90 would remain in the soil at the Trinity Site. The rest of the Strontium-90 would have decayed into other elements through radioactive decay. It's important to note that Strontium-90 is a dangerous radioactive isotope that can cause cancer and other health problems if ingested or inhaled, so measures should be taken to prevent people from being exposed to it.

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The half reaction with a more positive standard reduction potential will proceed spontaneously in a redox reaction

The half reaction with a more positive standard reduction potential will undergo reduction when compared to the half reaction with a more negative standard reduction potential.

Oxidation-reduction reactions, often known as redox reactions, are a set of chemical reactions that involve electron transfer between reactants. In a redox reaction, one reactant is oxidized, losing electrons, while the other reactant is reduced, gaining electrons.

The oxidation half-reaction is the process of losing electrons and increasing the oxidation number, whereas the reduction half-reaction is the process of gaining electrons and decreasing the oxidation number. The total reaction is referred to as the redox reaction.

Half-reaction:Half-reaction refers to the two parts of an oxidation-reduction reaction that happen separately. A half-reaction must always be either an oxidation reaction or a reduction reaction. It also describes the movement of electrons and hydrogen ions in an equation.

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The solubility of carbon dioxide in water at the given pressure would be 8.45 g CO2 in 100 mL of water.  

According to Henry's law:

C = kH x P

where:

To solve this problem, we need to use the Henry's law constant for carbon dioxide in water at 20 \(^oC\), which is 0.0349 mol/L/atm. Let's convert the given solubility from mass/volume units to molar concentration units as follows:

Now we can use Henry's law to calculate the solubility of carbon dioxide in water at 5.50 atm:

Concentration from mol/L to mass/volume units:

0.192 mol/L x 44.01 g/mol = 8.45 g CO2 / 100 mL

Therefore, the solubility of carbon dioxide in water at 5.50 atm pressure is approximately 8.45 g CO2 in 100 mL of water at 20 \(^oC\).

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Answer:

Xenon is element 54. in a perfect atom it would have 54 neutrons

Answer:

refer to explanation in order V

Explanation:

Atomic number: 54

Protons: 54

Electrons: 54

Neutrons: 77

Mass Number: 131.293 U

6 (1/2): At the upper left is the atomic number, or number of protons. In the middle is the letter symbol for the element (e.g., H). Below is the relative atomic mass, as calculated for the isotopes found naturally on Earth. At the very bottom is the name of the element (e.g., hydrogen).

6 (2/2): On the periodic table, the mass number is usually located below the element symbol.

I hope this helped!

We can see here that the catalytic cycle for the hydrogenation of alkenes using Wilkinson's catalyst involves several steps.

Here's an overview of the catalytic cycle, including the necessary details:

i. Chemical structure of the catalyst:

Wilkinson's catalyst, also known as chloridotris(triphenylphosphine)rhodium(I), has the following chemical structure: [RhCl(PPh3)3]

ii. Molecular geometry of the catalyst:

The Wilkinson's catalyst has a trigonal bipyramidal geometry around the rhodium center. The three triphenylphosphine (PPh3) ligands occupy equatorial positions, while the chloride (Cl) ligand occupies an axial position.

iii. Type of reactions involved:

The catalytic cycle involves several reactions, including:

iv. Starting material, reagent, and solvent:

The starting material is an alkene, and the reagent is Wilkinson's catalyst ([RhCl(PPh3)3]). The reaction is typically carried out in a suitable solvent, such as dichloromethane (CH2Cl2) or tetrahydrofuran (THF).

v. Major and minor end-products:

The major end-product of the hydrogenation reaction is the fully saturated alkane, resulting from the addition of hydrogen across the double bond. The minor end-product may include cis- or trans-configured alkanes if the original alkene substrate possesses geometric isomers.

vi. Intermediates:

The intermediates in the catalytic cycle include:

These intermediates play a crucial role in facilitating the hydrogenation reaction and enabling the catalytic cycle to proceed.

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Answer:

If they all had the same eye color it would probably be hazel, but If they did not then it would either be blue or brown.

Explanation:

Hope this helps

Answer:

Possible reasons why EA, or electronegativity, is a positive quantity for oxygen atom include:

Explanation:

We are given the molarity of the solution, the molarity corresponds to the following expression:

That is, in one liter of solution there will be 0.259 moles of calcium sulfate.

We are asked to find the volume to have 4.45g, let's see how many moles are equivalent. To do this we divide the required weight by the molecular weight (MW) of calcium sulfate.

MW of calcium sulfate = 136.1 g/mol

Now we apply a rule of three to know the required volume. In the same operation, we can make the conversion from liters to milliliters, since the answer is asked in milliliters.

So, we will need 126.24 mL to supply 4.45 g from a 0.259M calcium sulfate solution

Explanation:

An atom undergoes alpha decay by losing a helium atom.

So when bismuth undergoes alpha decay, we have;

²¹⁰₈₃Bi --> ⁴₂He + X

Mass number;

210 = 4 + x

x = 206

Atomic number;

83 = 2 + x

x = 81

The element is Thallium. The symbol is Ti.

For the second part;

X --> ⁴₂He + ²³⁴₉₀Th

Mass number;

x = 4 + 234 = 238

Atomic Number;

x = 2 + 90 = 92

The balanced nuclear equation is;

²³⁸₉₂U --> ⁴₂He + ²³⁴₉₀Th