Chemical Formulas, Equations, and Reactions

Nitric acid has the chemical formula HNO₃. How many atoms of nitrogen are in the formula?

• 0

• 1

• 3

• 5

Tags

NGSS.MS-PS1-1

A scientist analyzes a substance that is produced in a chemical reaction. The data show that each molecule of this product has three hydrogen atoms for every carbon atom. Which could be the formula for the substance?

• CH₄

• C₂H₆

• C₃H₈

• C₃H₆

Tags

NGSS.MS-PS1-1

A model of a molecule is shown. Which substance could the model represent.

• BH₃

• H₂CO

• H₂O₂

• NaOH

Tags

NGSS.MS-PS1-1

Dolomite, CaMg(CO₃)_{2, is a mineral used as an ingredient in concrete. How many carbon atoms are represented in the formula} CaMg(CO₃)₂?

• 1

• 2

• 3

• 6

Tags

NGSS.MS-PS1-1

Which of these formulas does NOT contain the same number of nitrogen atoms as nitrous oxide, N₂O?

• NH₄NO₃

• Cu(NO₃)₂

• (NH₄)₂CO₃

• NaCN

Tags

NGSS.MS-PS1-1

Potassium bitartrate, also known as cream of tartar, is a white powder sometimes used in cooking. The formula for cream of tartar is shown below.

KC₄H₅O₆

What is the total number of atoms shown in the formula?

Tags

NGSS.MS-PS1-1

The table shows the chemical formulas for four different compounds. In which compounds is the number of oxygen atoms four times the number of sulfur atoms?

• Compounds 1 and 4 only

• Compounds 3 and 4 only

• Compounds 1, 3, and 4

• Compounds 2, 3, and 4

Tags

NGSS.MS-PS1-1

Which of these activities with eggs involves a chemical change?

• Frying a raw egg

• Beating eggs and milk together

• Drawing on the shell of a hard-boiled egg

• Breaking a raw egg

Tags

NGSS.MS-PS1-2

NGSS.MS-PS1-5

Which of the following involves a physical change but no chemical change?

• Nails rusting

• Paper burning

• Sugar dissolving

• Leaves decaying

The photo shows a solid as it drops into water and starts producing bubbles. Which statement correctly explains the changes in the sold?

• The solid is dissolving, so a chemical reaction is happening.

• The formation of bubbles indicates that a chemical reaction is happening.

• Since bubbles contain only gas, a chemical reaction is not happening.

• Since no new solid is present, a chemical reaction is not happening.

Tags

NGSS.MS-PS1-2