SHHS Mid-Unit 3 Assessment Review

Which are postulates of Dalton's Atomic Theory?

• Atoms combine in whole number ratios to form compounds

• The atom is indivisible

• All matter is made up of atoms.

• Atoms of the same element have a different number of protons.

If there are too many or too few neutrons, what can happen?

• The elements can form ions.

• A chemical reaction can occur.

• The protons can fuse with other protons.

• The nucleus can become unstable.

In what period on the periodic table will this atom be found?

• 2nd

• 14th

• 1st

• 3rd

Which is true about the atomic number?

• It can change for isotopes of the same element.

• It always has a decimal in it.

• It equals the number of protons in an element.

• It determines the number of protons and neutrons in an element.

What would the charge be on the ion when using the model provided?

• 4+

• 1+

• 2+

• 2-

Using the picture provided, what is the atomic number of this ion?

• 4

• 3

• 5

• 2

Match the term to the correct definition.

• Neutron

• Negatively charged sub-atomic particle

• Anion

• Negative Charge (gained electrons)

• Electron

• Positive Charge (lost electrons)

• Proton

• Postively Charged Subatomic Particle

• Cation

• Neutral

If Magnesium (Mg) has 12 neutrons, 12 protons, and 10 electrons, which would be the correct ion symbol?

• Mg

• Mg¹

• Mg ⁺

• Mg ²⁺

• Mg ^3-

Which experiment proved that there was a nucleus at the center of the atom?

• Oil Drop Experiment

• Thomson's Cookie Experiment

• Plum Pudding Experiment

• Gold Foil Experiment

If 93% of Silicon is Silicon-28, 4% is Silicon-29, and 3% is Silicon-30. Which isotope will the average atomic mass be closest to?

• Silicon-28

• Silicon-29

• Silicon-30

• There is not enough information to determine the isotope.