5.3 Chemical Formula

What does the subscript in a chemical formula represent?

• The number of molecules in a compound

• The number of protons in an atom

• The number of atoms of an element in a molecule

• The number of electrons shared between atoms

Which of the following is the correct chemical formula for water?

• H2O2

• CO2

• H2O

• NaCl

Tags

NGSS.MS-PS1-1

What type of bond is present in ionic compounds?

• Covalent bonds

• Metallic bonds

• Ionic bonds

• Hydrogen bonds

Which of the following compounds is an example of a covalent compound?

• Sodium chloride

• Calcium iodide

• Hydrogen peroxide

• None of the above

How many oxygen atoms are there in a molecule of carbon dioxide?

• 1

• 2

• 3

• 4

Tags

NGSS.MS-PS1-1

What is the ratio of hydrogen to oxygen atoms in a molecule of water?

• 1:1

• 2:1

• 1:2

• 2:2

Tags

NGSS.MS-PS1-1

What distinguishes a chemical compound from a mixture like oil and vinegar salad dressing?

• A compound has a variable ratio of elements, while a mixture has a fixed ratio.

• A compound can only be separated by chemical means, while a mixture can be separated physically.

• A compound has a fixed ratio of elements, while a mixture has a variable ratio.

• A compound is always liquid, while a mixture can be in any state of matter.

What is the chemical formula for the ionic compound consisting of one lithium ion (Li⁺) to one fluoride ion (F⁻)?

• LiF

• Li₂F

• LF₂

• LiF₂

Tags

NGSS.MS-PS1-1

When writing the chemical formula for a covalent compound, which element is written first?

• The element that is farther to the right in the periodic table

• The element with the higher atomic number

• The element that is farther to the left in the periodic table

• The element with the lower period number

What is the chemical formula for the covalent compound nitrogen dioxide?

• NO

• N₂O

• NO₂

• N₂O₂

Tags

NGSS.MS-PS1-1