Chemistry Year 9

Where is most of the mass in an atom located?

• in the nucleus

• in the protons

• in the neutron

• in the electron

What is the mass number?

• the number of protons

• the number of electrons

• the number of neutrons

• the sum of the number of protons and neutrons found in the nucleus

What is the atomic number?

• number of protons

• number of electrons

• number of neutrons

• sum of number of protons and neutrons in the nucleus

Oxygen's atomic number is 8. This means that an oxygen atom must have...

• 8 nucleus

• 8 protons

• 8 neutrons

• a mass number of 8

Carbon 12 has a mass number of

• 10

• 8

• 6

• 12

Carbon 12, Carbon 13 and Carbon 14 are examples of an

• cation

• anion

• ion

• isotope

Which best describes an electron

• smaller mass than a proton. A negative charge

• smaller mass than a proton. A positive charge

• Greater mass than a proton. A negative charge

• Greater mass than a proton. A positive charge

Which subatomic particle determines a atoms ability to bond with other atoms

• number of protons in outer shell

• number of nucleus in outer shell

• number of electrons in outer shell

• neutrons in outer shell

Which subatomic particle has a neutral charge

• proton

• electron

• neutron

• nucleus

Valence electrons are found

• inside the nucleus

• in unstable atoms

• in the outer shell of an atom

• in the inner shell of an atom