Question

1. Which statement describes the properties of both elements that have just one valence electron and elements that have seven valence electrons?

They are highly reactive.
They are gases at room temperature.
They exist in nature as pure elements.
They easily give up an electron.

2. What are properties of the group of elements on the periodic table that have seven valence electrons?
High reactivity, metallic
High reactivity, nonmetallic
Low reactivity, metallic
Low reactivity, nonmetallic

3. When oxygen forms an ion, what is its charge?
2+
3+
2-
3-

4. Which of the following is a possible formula unit?
Li3Al
ClO2
LiCl
CaN


5. What does a Lewis structure show that makes it a useful model for a molecule?
All electrons in the atoms
Angles between bonds
How electrons are shared
Relative sizes of atoms

H
I
H - C - H
I
H

6. The structure looks like the lay out I’ve created above. The Lewis structure for methane, CH4 is shown. How many valence electrons does each hydrogen atom in the molecule have?
1
2
4
8


H-H
7. The structure looks like the layout I’ve created above. The Lewis structure for a hydrogen molecule, H2, is shown. The line segment in the structure shows that the two atoms
share one valence electron.
share two valence electrons.
have one unshared electron.
have two unshared electrons.

8. What is the molar mass of NaNO3?
42.0 g/mol
53.0 g/mol
73.0 g/mol
85.0 g/mol

Answer 1

Q1. They are highly reactive. Q2. High reactivity, nonmetallic. Q3. Oxygen has an ion charge of -2. Q4. LiCl I believe. Q5. How electrons are shared. Q6 1. Q7. Share 2 valence electrons, I believe.

Answer 2

1) They are highly reactive.

2) They are highly reactive and are non metallic.

3) -2

4)LiCl

5) How electrons are shared

6) Each hydrogen electron has one valence electron

7) share two valence electrons

8) 85.0 g/mol

Step-by-step explanation:

1) As both the kind of elements are ready to give or taken one electron, to attain noble gas configuration or full filled stability, they are highly reactive.

The element which has just one electron in valence shell will give the electron easily.

The element which has seven valence electrons will accept one electron easily.

2) Halogen have seven valence electrons. They are highly reactive as the are ready to take one electron. As they cannot give electrons they are non metals.

3) Generally oxygen can accept two electrons so its charge is "-2"

4) Formula unit is generally for ionic compound. LiCl is an ionic compound.

5) In lewis structure we write elements are then distribute electrons over all the atoms. It shows the number of bonded electrons, unshared or lone electrons as well.

6) The configuration of hydrogen is 1s1, thus it has only one valence electron/ atom.

7) In each covalent bond there are two shared electrons (shared by two atoms bonded).

8) molar mass = atomic mass of Na + Atomic mass of N + 3 X atomic mass of O

Molar mass = 23 + 14 + 3(16) = 85.0 g/mol