Science Quiz - Grade 8

A subatomic particle that has a negative charge is called a(n)……………………

• molecule.

• electron.

• element.

• compound.

A subatomic particle that has a positive charge is called a(n)……………………

• proton

• electron.

• element.

• neutron

A subatomic particle that has no charge is called a(n)……………………

• proton

• electron.

• element.

• neutron

The elements in the modern periodic table arranged by increasing ……………………………

• the number of protons in the nucleus.

• the electric charge of the nucleus.

• the number of neutrons in the nucleus.

• atomic mass.

Semiconductors are elements that….

• have large atomic masses but small atomic numbers.

• don't form compounds.

• can conduct heat and electricity under certain conditions.

• extremely hard.

Elements that belong to the same group have the same number of …

• valence electrons.

• inner electrons.

• neutral electrons.

• total electrons.

Whose model determined that an atom's positive charge is concentrated in the atom's center?

• Rutherford's

• Dalton's

• Democritus's

• Thomson's

Two different isotopes of an element have different …

• numbers of neutrons.

• numbers of protons.

• numbers of electrons.

• atomic numbers.

The number of protons in nucleus of an atom

• atomic number

• mass numbers

• atomic mass

Is the sum of the protons and neutrons in the atom.

• atomic number

• mass numbers

• atomic mass