Chemistry Introduction for 9th Grade

What is the smallest unit of matter?

• Molecules

• Cells

• Planets

• Atoms

In which state of matter do particles have the most energy?

• Liquid state

• Gaseous state

• Plasma state

• Solid state

How are elements arranged in the periodic table?

• Based on their color.

• Based on their melting point.

• Based on their atomic weight.

• Based on their atomic number.

What are macromolecules?

• Small molecules for life

• Medium-sized molecules for life

• Tiny molecules for life

• Large molecules necessary for life

Give an example of a chemical change.

• Iron rusting

• Boiling water

• Mixing salt and sugar

• Cutting paper

Give an example of a physical change.

• Freezing water into ice

• Burning paper into ashes

• Melting ice into water

• Boiling water into steam

How many protons are in a carbon atom?

• 4

• 10

• 8

• 6

What is the symbol for gold on the periodic table?

• Au

• Fe

• Pt

• Ag

What is the pH scale used to measure?

• volume of a solution

• acidity or alkalinity of a solution

• density of a solution

• temperature of a solution

What is the chemical formula for water?

• H2O

• HO

• O2

• H2