Unit 2: Atomic Theory

Atoms with the same number of protons, but different number of neutrons are called

• isotopes

• neutral

• ions

• isolines

This scientist used Alpha Particles and Gold Foil to discover the nucleus of the atom.

• JJ Thomson

• James Chadwick

• Ernest Rutherford

• Niels Bohr

Niels Bohr found that electrons move in definite orbits around the

• element

• atom

• nucleus

• sun

Thompson's model of negative electrons randomly distributed through a positively charged matrix is called the -

• plum pudding model

• atomos

• bohr model

• gold foil model

In 1911 I discovered that atoms have a positive particle called proton.

• Dalton

• Rutherford

• Chadwick

• Bohr

How do you find the mass number?

• Protons+Electrons

• Protons+Neutrons

• Protons+Neutrons+Electrons

• Calculate it using the percent abundance for each isotope

How do you find the average atomic mass?

• Protons+Electrons

• Protons+Neutrons

• Protons+Neutrons+Electrons

• Calculate it using the percent abundance for each isotope

How does Carbon-12 and Carbon-14 differ?

• # of protons

• Mass #

• # of neutrons

• Mass # and # of neutrons

An atom with 3 protons, 2 electrons, and 4 neutrons will be:

• Lithium-7 with a -1 charge

• Lithium-5 with no charge

• Lithium-5 with a +1 charge

• Lithium-7 with a +1 charge

How many neutrons does Thorium-182 have?

• 92

• 90

• 182

• 129