In the modern periodic table shown in Figure 1 above, find the element named lead (Pb). How many protons do atoms of lead have? To which class of elements does lead belong?

Answer:

It is the second answer; A dark solid formed on the zinc.

Explanation:

This is the correct answer because when a solid is formed it is called a precipitate, which is commonly known as a chemical reaction.

The evidence that supports the student's inference is a dark solid formed on the zinc.

When zinc is added to copper sulphate (CuSO4) solution, due to more reactivity of zinc, copper is replaced by zinc and forms zinc sulphate precipate.

Thus, the student is correct, there will be a chemical reatcion between the zinc and  copper sulphate (CuSO4) solution, producing a dark solid substance.

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Answer: C

Explanation:

The force of gravity is proportional to the amount of mass in the system, and is inversely proportional to the separation distance between the two masses.

Adding mass to one of the objects would increase the gravitational field it produces, which in return increases the force of gravity.

Increasing the charge of one of the objects would technically add mass to the system, but it can be considered negligible. The adding of charge would cause an attraction between the two objects, but that is not the gravitational force. It is the Coulomb force.

Reducing the mass of one of the objects would decrease the gravitational field it produces, which would cause the force of gravity to decrease. This is the answer.

Moving the objects closer would cause the denominator of the force equation to decrease. A smaller denominator would cause the equality to increase, aka the gravitational force.

\(F=GMm/r^2\)

The empirical formula of polyethylene can be determined by converting the given percentages of carbon (C) and hydrogen (H) into grams. To find the grams of each element, we assume a 100.0 g sample of polyethylene.

For carbon:

Mass of carbon = 86.0% × 100.0 g = 86.0 g

For hydrogen:

Mass of hydrogen = 14.0% × 100.0 g = 14.0 g

Therefore, in a 100.0 g sample of polyethylene, there are 86.0 grams of carbon and 14.0 grams of hydrogen.

The empirical formula of a compound represents the simplest whole-number ratio of atoms present in the compound. To determine the empirical formula, we need to find the ratio of carbon to hydrogen in terms of moles.

First, we convert the masses of carbon and hydrogen into moles using their respective molar masses. The molar mass of carbon is approximately 12.01 g/mol, and the molar mass of hydrogen is approximately 1.008 g/mol.

Number of moles of carbon = 86.0 g / 12.01 g/mol ≈ 7.162 mol

Number of moles of hydrogen = 14.0 g / 1.008 g/mol ≈ 13.89 mol

Next, we divide the number of moles of each element by the smallest number of moles to get a simplified ratio.

Carbon: Hydrogen ≈ 7.162 mol : 13.89 mol ≈ 1 : 1.939

Since we want to express the ratio in whole numbers, we multiply both sides by 2 to get a whole number ratio.

Carbon: Hydrogen ≈ 2 : 3.878

Rounding to the nearest whole number, we find that the empirical formula of polyethylene is CH₂.

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Answer:

The correct answer would be 40 m/s

Explanation:

The reason 40 m/s is the correct answer is because m/s stands for meters per second.

Hope this helps you with what you're working on! :D

Answer:

40 m/s north

Explanation:

Velocity is a vector quantity, so it have both direction and magnitude.

Answer:

Mendeleev had left the noble gases out of his periodic table.

Explanation:

Mendeleev's periodic table is pictured in the image attached to the question.

Mendeleev's table obviously lacked the noble gases. The reason for this grave omission is simple; the noble gases were not known as at the time when he formulated his periodic table. There weren't any known elements  whose properties were similar to the  properties of the noble gases. This would have lead him to suspect their existence.

Answer:

Fatty foods become rancid due to the process of rancidity

Answer:

Protegerte Freddy Gerrard Reverte Freddy Buffett irrefutables

Explanation:

Princesa fashion casadas libres

Answer:

Condensation

Explanation:

When a gas changes into a liquid, it is called condensation.

The first most obvious thing to note is when naming transitional metals, you have to state its charge with roman numerals (except for 1 if I remember correctly). For example, Iron (lll), iron has a charge of 3.

Answer is closest to option (a) 2850 g. The mole is a fundamental concept in chemistry and is used extensively in calculations involving chemical reactions and stoichiometry.

What is Mole?

The mole is used to convert between the mass of a substance and the number of particles it contains. For example, the molar mass of a substance (the mass of one mole of that substance) can be used to convert the mass of a sample to the number of moles of that substance present.

The balanced chemical equation for the reaction is:

P4O10(s) + 6H2O(l) → 4H3PO4(aq)

From the equation, we can see that for every 6 moles of water that react, 4 moles of H3PO4 are produced.

So, to calculate the moles of H3PO4 produced, we first need to calculate the moles of water that react. The question states that 43.6 moles of water react, so we can use this value to calculate the moles of H3PO4 produced:

moles of H3PO4 = (4/6) x 43.6 = 29.07 moles

Finally, we can use the molar mass of H3PO4 to convert moles to grams:

grams of H3PO4 = moles of H3PO4 x molar mass of H3PO4

= 29.07 moles x 98 g/mol

= 2848.86 g

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Answer:

Option B. pentan-1-ol

Explanation:

We'll begin by writing the name of the compound.

The name of the compound above is pentylpropanoate.

From the name of the compound and the structure, we can suggest the following equation:

CH3CH2COOH + HOCH2CH2CH2CH2CH3 —> CH3CH2COOCH2CH2CH2CH2CH3 + H2O

Thus,

Propanoic acid + pentan-1-ol —> pentylpropanoate + water.

Therefore, the alcohol used in the reaction is pentan-1-ol

At equilibrium, the number of moles of \(Cl_2\) (g) will be 0.2025 mol.

1: Write the balanced chemical equation:

\(C_O\)(g) + \(Cl_2\)(g) ⟶ \(C_OCl_2\)(g)

2: Set up an ICE table to track the changes in moles of the substances involved in the reaction.

Initial:

\(C_O\)(g) = 0.3500 mol

\(Cl_2\)(g) = 0.05500 mol

\(C_OCl_2\)(g) = 0 mol

Change:

\(C_O\)(g) = -x

\(Cl_2\)(g) = -x

\(C_OCl_2\)(g) = +x

Equilibrium:

\(C_O\)(g) = 0.3500 - x mol

\(Cl_2\)(g) = 0.05500 - x mol

\(C_OCl_2\)(g) = x mol

3: Write the expression for the equilibrium constant (Kc) using the concentrations of the species involved:

Kc = [\(C_OCl_2\)(g)] / [\(C_O\)(g)] * [\(Cl_2\)(g)]

4: Substitute the given equilibrium constant (Kc) value into the expression:

1.2 x \(10^3\) = x / (0.3500 - x) * (0.05500 - x)

5: Solve the equation for x. Rearrange the equation to obtain a quadratic equation:

1.2 x \(10^3\) * (0.3500 - x) * (0.05500 - x) = x

6: Simplify and solve the quadratic equation. This can be done by multiplying out the terms, rearranging the equation to standard quadratic form, and then using the quadratic formula.

7: After solving the quadratic equation, you will find two possible values for x. However, since the number of moles cannot be negative, we discard the negative solution.

8: The positive value of x represents the number of moles of \(Cl_2\)(g) at equilibrium. Substitute the value of x into the expression for \(Cl_2\)(g):

\(Cl_2\)(g) = 0.05500 - x

9: Calculate the value of \(Cl_2\)(g) at equilibrium:

\(Cl_2\)(g) = 0.05500 - x

\(Cl_2\)(g) = 0.05500 - (positive value of x)

10: Calculate the final value of \(Cl_2\) (g) at equilibrium to get the answer.

Therefore, at equilibrium, the number of moles of \(Cl_2\) (g) will be 0.2025 mol.

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Answer:

Explanation:

C₇H₁₆ is heptane and it has nine isomers (n-heptane and the remaining 8 constitutional isomers). Constitutional isomers are compounds with the same molecular formula but different structural formula or atom connectivity.

The constitutional isomers of n-pentane are 2-methylhexane, 3-methylhexane, 2,2-dimethylpentane, 2,3-dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, 3-ethylpentane and 2,2,3-trimethylbutane. There structures are in the picture attached

1) There are only single bonds between the carbon atoms, so the ending is 'ane'. Thus, the answer is 2-methylbutane.

2) There is one triple bond between one pair of carbon atoms, so the ending is 'yne'. So, the answer is 2-butyne.

3) There is one double bond between one pair of carbon atoms, so the ending is 'ene'. So, the answer is 2-butene.

Lewis electron dot notation is a method for representing the valence electrons in an atom. In this notation, the valence electrons are shown as dots around the symbol of the element. The number of dots represents the number of valence electrons.

The Lewis electron dot notation is a useful tool for understanding the chemical behavior of elements. It allows us to see how many valence electrons an atom has and how they are distributed. This information can be used to predict the types of chemical bonds that an atom is likely to form. For example, the Lewis electron dot notation for nitrogen is:
N: ·
Nitrogen has five valence electrons, so there are five dots around the symbol.
In addition to representing individual atoms, the Lewis electron dot notation can also be used to represent molecules. In a molecule, the dots represent the shared electrons between the atoms.  The Lewis electron dot notation is an important concept in chemistry that helps us to understand the properties and behavior of atoms and molecules.

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The grams of iron(IIl) chloride required to react completely with all the available silver nitrate is 162.2 grams.

Grams are the value or SI unit of mass. Mass can be calculated in grams and kilograms. 1 kg = 1000g.

The chemical equation will be

3 AgNO₃ + FeCl₃ = Fe(NO₃)₃ + 3 AgCl

To calculate the mass, we would divide the moles with the molar mass of the compounds

FeCl₃ = moles / molar mass

Molar mass of FeCl₃ = 162.2 grams

1 mole = x mole/ 162.2 grams

x = 162.2 grams

Thus, the grams of iron chloride required is 162.2 grams.

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The difference between all three Magnesium, Mg isotopes is in; the number of neutrons.

Isotopy is a property of elements in which case the element has two or more types of atoms that have the same atomic number and hence, same position in the periodic table, but differ in nucleon numbers due to different numbers of neutrons in their nuclei.

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ANSWER

STEP-BY-STEP EXPLANATION:

You are given the below expression from the question provided

Answer:

Nitrogen is the limiting reactant, and 3.74

grams of ammonia is formed.

Hope this helps

'Chromatography' is defined as an analytical technique commonly used for separating a mixture of chemical substances into its individual components, so that the individual components can be thoroughly analyzed.

Chromatography is simply defined as a process for separating components of a mixture. In order to start the process, the mixture that is dissolved in a substance is called the mobile phase, which carries it through a second substance called the stationary phase.

The process of chromatography is based on the principle that components of a mixture are separated when the mixture which is a mobile phase is moved through a stationary phase, resulting in some components of the mixture being attached to the stationary phase material and the remaining mixture is passed along as the mobile phase.

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Answer:

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Answer:

C₂H₆(g) + 7/2 O₂(g) → 2 CO₂ + 3 H₂O

Explanation:

To balance equations of combustion (Chemical + O₂ producing CO₂ and water you must do:

1. Write as CO₂ as carbons in the chemical you have:

For the reaction:

C₂H₆(g) + O₂(g) → CO₂ + H₂O

As you have 2 carbons in ethane:

C₂H₆(g) + O₂(g) → 2 CO₂ + H₂O

2. Write the half of H₂O as hydrogen you have:

There are 6 hydrogens → You must place 3 H₂O:

C₂H₆(g) + O₂(g) → 2 CO₂ + 3 H₂O

3. The last step is to write the half of oxygens you have in products.

4 Oxygens from CO₂ and 3 from water:

The balancing of chemical equations is based on the law of conservation of mass.

How could a chemical process be made to balance out? Which integers can be changed, and which cannot?

When an equation is balanced, the coefficients can only be changed (the numbers in front of molecules or atoms).

The coefficients are indicated by the numerals in front of the molecule. Subscripts are the smaller numerals found following atoms. These cannot be changed while balancing chemical equations!

How is a chemical equation brought to equilibrium?

the algebraic balancing technique. Chemical equations can be balanced by assigning algebraic variables as stoichiometric coefficients to each species in the unbalanced chemical equation.

Equations in mathematics are used to calculate the values of each of these variables

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Answer:

products have a higher potential energy than the reactants

Explanation:

The total potential energy of the system increases for the endothermic reaction as the system absorbs energy from the surroundings. The total potential energy of the system decreases for the exothermic reaction as the system releases energy to the surroundings

The endothermic reaction results in the increase in the potential energy of the product than the reactant. Thus, option C is correct.

The endothermic reaction is given as one in which the heat is absorbed by the system, and no energy is released.

The increase in the heat of the product is mediated that governs the increase in the potential energy of the product than the reactant due to absorption. Thus, option C is correct.

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Answer:

\(c=0.127\ J/g^{\circ} C\)

Explanation:

Given that,

Mass of the sample, m = 275 g

It required 10.75 kJ of heat to change its temperature from 21.2 °C to its melting temperature, 327.5 °C.

We need to find the specific heat of the metal. The heat required by a metal sample is given by :

\(Q=mc\Delta T\)

c is specific heat of the metal

\(c=\dfrac{Q}{m\Delta T}\\\\c=\dfrac{10.75\times 10^3\ J}{275\times (327.5 -21.2)}\\\\=0.127\ J/g^{\circ} C\)

So, the specific heat of metal is \(0.127\ J/g^{\circ} C\).

The molarity of the sodium hydroxide solution is 0.09111 M.

What is Molarity?

Molarity is a measure of the concentration of a solution. It is defined as the number of moles of solute dissolved in one liter of solution.

Molarity is an important concept in chemistry because it allows us to quantify the amount of solute in a solution and to make predictions about the behavior of the solution in various chemical reactions.

First, we can calculate the number of moles of potassium hydrogen phthalate using its molecular weight:

moles of KHP = mass / molecular weight

moles of KHP = 0.600 g / 204.22 g/mol

moles of KHP = 0.002938 mol

Since one mole of KHP reacts with one mole of NaOH, we know that there are also 0.002938 moles of NaOH in the titrated solution. We can calculate the molarity of the NaOH solution using the formula:

molarity = moles of solute / volume of solution (in liters)

First, we need to convert the volume of the NaOH solution from milliliters to liters:

volume of NaOH solution = 32.21 mL = 0.03221 L

Now we can calculate the molarity of the NaOH solution:

molarity = 0.002938 mol / 0.03221 L

molarity = 0.09111 M

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Answer:

B. basic

Explanation:

Because acidic is sour in test, salt is tasty in taste, and neutral neither bitter, tasty and nor sour