Compounds

Question 1

How many atoms of each element are in 4Na3PO4?

Revolt · Accepted Answer

12 sodium, 4 phosphorus, 16 oxygen

Question 2

Two models of the same compound are shown.

Revolt · Accepted Answer

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

Question 3

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

Revolt · Accepted Answer

8

Question 4

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?

Revolt · Accepted Answer

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

Question 5

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

Revolt · Accepted Answer

2 phosphorus and 5 oxygen

Question 6

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

Revolt · Accepted Answer

It is made up of two elements.

Question 7

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

Revolt · Accepted Answer

2

Question 8

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

Revolt · Accepted Answer

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

Question 9

Which is the best description of a molecule?

Revolt · Accepted Answer

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

Question 10

Two models of the same compound are shown.

Revolt · Accepted Answer

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

Compounds Answers