Grade 9 End of year Chemistry review

Front

What is the trend of atomic radius across a period and down a group?

Back

Atomic radius decreases across a period and increases down a group.

Front

What is the mass of an atom's nucleus composed of?

Back

The mass of an atom's nucleus is the sum of protons and neutrons.

Front

What is a qualitative observation? Give an example.

Back

A qualitative observation describes characteristics or qualities. Example: Iron is denser than aluminum.

Front

What is the correct statement about the movement of molecules in ice?

Back

The molecules vibrate about their fixed position.

Front

What is the element name of the atom with atomic number 9?

Back

Fluorine.

Front

Define electronegativity.

Back

Electronegativity is the ability of an atom to attract electrons in a chemical bond.

Front

What happens to ionization energy across a period?

Back

Ionization energy increases across a period.

Front

What is the difference between a chemical change and a physical change?

Back

A chemical change results in the formation of new substances, while a physical change does not.

Front

What is the definition of a molecule?

Back

A molecule is a group of two or more atoms bonded together.

Front

What is the significance of the periodic table?

Back

The periodic table organizes elements based on their atomic number and properties.