Unit 1 Review, AOS 1, Part 1

Consider the following electrostatic forces:

I. Attraction between oppositely charged particles

II. Repulsion between positively charged particles

III. Repulsion between negatively charged particles.

The electrostatic forces operating in an atom are:

• I only

• I and II only

• I and III only

• I, II, and III

Zinc is an element. Therefore:

• zinc has no isotopes

• all zinc atoms are identical

• zinc atoms always contain the same number of protons

• zinc atoms contain equal numbers or protons and neutrons

• contain either 63 or 65 protons.

• contain either 34 or 36 neutrons.

• have a mass number of 63.55

• have an atomic number of 29 or 31.

An ion that contains 11 protons, 12 neutrons, and 10 electrons will have a mass number and charge, respectively, corresponding to:

• 11 -1

• 11 +1

• 23 -1

• 23 +1

Main group elements are placed into groups on the periodic table according to each element's:

• mass number

• atomic number

• number of occupied electron shells

• number of electrons in the outer shell

Answer explanation

Exception to the rule.

Chromium prefers to have a half filled d-subshell.

Remember - how the orbitals fill - one e- in each orbital and then it goes back and fills the extra space.

The 3d subshell has:

• 3 orbitals and can hold up to 3 electrons.

• 3 orbitals and can hold up to 6 electrons.

• 5 orbitals and can hold up to 10 electrons.

• 5 orbitals and can hold up to 15 electrons.

Which one of the following metals reacts most readily with oxygen?

• Na

• K

• Mg

• Ca

Which one of the following properties is not typical of transition metals?

• They are softer and more malleable than main group metals.

• Their ions can have more than one valency.

• Their compounds are often coloured.

• They are often used as catalysts.

Predict which one of the following ionic compounds will have the highest melting point.