2.3 Chemistry Test Review

How many valence electrons are present in question 25?

1

Write the electron configuration and noble gas notation for Antimony (Sb).

1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p3

How many valence electrons are present in question 23?

6

Potassium (K) has an ionization energy of 419 kJ/mol. Bromine (Br) has an ionization energy of 1140 kJ/mol. Which of the following is a possible explanation for the trend?

As you move across a period, the nuclear charge increases with more protons, but the electrons will be on the same energy level. Atoms tend to not want to lose electrons as they get close to have 8 valence electrons, octet rule.

The least amount of energy: Explain your choice. a. magnesium or barium

Barium has 3 more levels of electrons further away from the nucleus

which element would require the most energy to remove an electron? Explain your choice. a. calcium or bromine

Bromine has a stronger nuclear charge (more protons) that will pull on the 4th level electrons more.

State the trends for atomic radius on the periodic table? Left to right:

Decrease

Which element has the noble gas configuration of [Ar] 4s2 4p1?

Gallium

State the trends for atomic radius on the periodic table? Top to bottom:

Increase

If the atomic radius of aluminum is 118 pm and phosphorus is 98 pm, approximately what would be the atomic radius of silicon?

It should be right in the middle like the placement on the periodic table, 108pm

which element would require the most energy to remove an electron? Explain your choice. b. lithium or cesium

Lithium has 4 less levels of electrons, making them closer to the nucleus.

which element oxygen or sulfur has the greatest electronegativity?

Oxygen

Which element has the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s1?

Potassium

Which element has the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p4?

Selenium

Which element has the noble gas configuration of [Ne] 3s1?

Sodium

The least amount of energy: Explain your choice. b. sodium or chlorine

Sodium has a smaller nuclear charge that pulls on the electrons less than chlorine.

Which of the following elements requires the LEAST amount of ionization energy: Strontium (Sr) or Silver (Ag)? Explain your answer choice (Why does it have the least amount of ionization energy?)

Strontium will require the least amount of energy to remove an electron because it has a weaker nuclear charge than silver, and since both have electrons to the fifth level, strontium will not attract them as much.

According to the ionic radius trend, what happens to the size of an atom when it gains electrons to become an anion (negative ion)?

The ion will be larger than the neutral atom due to gaining more electrons for the nucleus to attract.

How does the size of the atom change when it forms a cation (positive ion)?

The ion will be smaller than the neutral atom because it will lose the electrons from the valence level and lose that level of electrons

State the trends for ionization energy and electronegativity on the periodic table. Top to bottom.

decrease

Define ionization energy

energy required to remove the first electron from the atom to make it an ion.

State the trends for ionization energy and electronegativity on the periodic table. Left to right.

increase

Define anion

negative ions formed mainly by nonmetals when they gain their valence electrons.

Na+1 & Ne

pairs of atoms would have the SAME electron configuration

Define cation

positive ions formed mainly by metals when they lose their valence electrons.

Define electronegativity

the attraction an atom has for electrons.