Chemical Bonding

Question 1

Terminology;

1) noble gas core
2) psuedo noble gas core
3) valence e
4) paramagnetic
5) diamagnetic

Answer 1

1) [He} 1s
2) [X] (n-1)d^10
3) e outside the noble gas core
4) weakly attracted to magnetic fields (unpaired e)
5) not (4)

Question 2

How is the current periodic table arranged?

Answer 2

The elements are arranged by atomic number, their physical and chemical properties vary periodically.

Question 3

Give 3 main physical properties of an atom and discuss the periodic trends according to the periodic table.

Answer 3

1) Atomic radius;
-Effective nuclear charge : A positive charge an e experiences from the nu.
-ENC increases across a period. Therefore AR decreases across a period.
2) First Ionization Energy : The minimum E needed to remove the highest-E e from a neutral atom in gaseous state.
- IE1 increases across a period.
3) Electron Affinity : The E released when a neutral atom picks up an e.
- trend varies according to e config.
(1-stable, 2-negative, 13-stable, 14-stable, 15-notS, 16-stable, 17-veryS, 18-negative)

[4) Electronegativity(X) : A measure of the ability of an atom in a molecule to draw bonding electrons to itself.
X = (IE + EA)/2]

Question 4

1) What is a chemical bond?
2) Why do they form?
3) Name the main types of bonds (3)

Answer 4

1) A strong attractive force that exists between certain atoms in a substance.
2) Atoms in s and p blocks will form bonds to obtain an octet of e.
3) Ionic, Covalent, Metallic

Question 5

What is a covalent bond?

Answer 5

A chemical bond formed by sharing a pair of electrons.

Question 6

What is coordinate covalent bond?

Answer 6

A chemical bond formed by one atom sharing both the electrons of the bond.

Question 7

What is polar covalent bond?

Answer 7

A covalent bond in which electrons spend more time near one atom than the other.