Answers HS Physical Science A - CR Summer School 2026Mixtures

Compounds Answers

13 verified answers

Free Preview

How many atoms of each element are in 4Na3PO4?

3 sodium, 1 phosphorus, 4 oxygen

4 sodium, 4 phosphorus, 4 oxygen

12 sodium, 1 phosphorus, 4 oxygen

12 sodium, 4 phosphorus, 16 oxygen

Free Preview

Which statement describes how chemical formulas, such as H2O, represent compounds?

They show the types of molecules that make up an atom.

They show the elements that make up a compound.

They show the three-dimensional shape of a molecule.

They show the types of bonds that exist between elements.

Two models of the same compound are shown.

Model B shows the types of elements in the compound, but Model A does not.

Model B shows the three-dimensional shape of the molecule, but Model A does not.

Model B shows how the atoms in the molecule are connected, but Model A does not.

Model B shows the number of atoms of each element in the molecule, but Model A does not.

There are several different models that represent compounds. One type of model is shown.

a structural formula

a chemical formula

a space-filling model

a ball-and-stick model

How many atoms of oxygen in the chemical formula 2Ca(ClO2)2?

The compound magnesium phosphate has the chemical formula Mg3(PO4)2. In this compound, phosphorous and oxygen act together as one charged particle, which is connected to magnesium, the other charged particle.What does the 2 mean in the formula 5Mg3(PO4)2?

There are two elements in magnesium phosphate.

There are two molecules of magnesium phosphate.

There are two magnesium ions in a molecule of magnesium phosphate.

There are two phosphate ions in a molecule of magnesium phosphate.

Elena makes the table below to determine the number of atoms of each element in the chemical formula 3(NH4)2SO4.What mistake did Elena make?

She should not have multiplied the sulfur atoms by the subscript 4.

She should not have multiplied the nitrogen atoms by the subscript 2.

She should not have multiplied the oxygen atoms by the coefficient 3.

She should not have multiplied the hydrogen atoms by the coefficient 3.

How many atoms of each element are in the chemical formula P2O5?

2 phosphorus and 5 oxygen

5 phosphorus and 2 oxygen

1 phosphorus and 5 oxygen

2 phosphorus and 1 oxygen

What does the chemical formula CaCl2 show about the compound it represents?

It is made up of one element.

It is made up of two elements.

It is made up of three elements.

It is made up of four elements.

How many atoms of nitrogen are in the chemical formula Ni(NO3)2?

Which statement correctly describes why a compound is a pure substance?

A compound is not a pure substance because each of its molecules is made up of the atoms of two or more different elements.

A compound is a pure substance because its molecule cannot be broken down into simpler particles by physical means.

A compound is not a pure substance because it is not an element, and only elements are pure substances.

A compound is a pure substance because it consists of two different elements, which are pure substances.

Which is the best description of a molecule?

A molecule of an element is composed of at least two types of atoms.

A molecule of a compound is composed of only one atom.

A molecule of a compound is composed of at least two atoms.

A molecule of an element is composed of exactly two types of atoms.

Two models of the same compound are shown.

Model A shows the types of elements in the compound, but Model B does not.

Model A shows the total number of atoms in the molecule, but Model B does not.

Model A shows the three-dimensional shape of the molecule, but Model B does not.

Model A shows the number of atoms of each element in the molecule, but Model B does not.

Did you find these answers helpful?