PRELIM: 3

Question 1

Chemical compounds are conveniently divided into two broad classes called _____________and ______________.

Answer 1

ionic compounds and molecular compounds.

Question 2

tend to have high melting points (500°C–2000°C) and are good conductors of electricity when they are in a molten (liquid) state or in solution.

Answer 2

Ionic compounds

Question 3

generally have much lower melting points and tend to be gases, liquids, or low melting-point solids. They do not conduct electricity in the molten state.

Answer 3

Molecular compounds

Question 4

is the attractive force that holds two atoms together in a more complex unit.

Answer 4

chemical bond

Question 5

Corresponding to the two broad categories of chemical compounds are two types of chemical attractive forces (chemical bonds):

Answer 5

ionic bonds and covalent bonds.

Question 6

is a compound in which covalent bonds are present

Answer 6

molecular compound

Question 7

is a chemical bond formed through the transfer of one or more electrons from one atom or group of atoms to another atom or group of atoms

Answer 7

ionic bond

Question 8

is a compound in which ionic bonds are present

Answer 8

ionic compound

Question 9

is a chemical bond formed through the sharing of one or more pairs of electrons between two atoms.

Answer 9

covalent bond

Question 10

A ____________ is the chemical symbol of an element surrounded by dots equal in number to the number of valence electrons present in atoms of the element.

Answer 10

Lewis symbol

Question 11

is an electron in the outermost electron shell of a representative element or noble-gas element

Answer 11

valence electron

Question 12

Lewis symbols, named in honor of the American chemist ________________, who first introduced them, are also frequently called electron-dot structures

Answer 12

Gilbert Newton Lewis

Question 13

A key concept in elementary bonding theory is that certain arrangements of valence electrons are more stable than others.

Answer 13

Octet rule

Question 14

The maximum number of valence electrons for any element is _______.

Answer 14

eight

Question 15

Determine the number of valence electrons in Mg

Answer 15

2

Question 16

Determine the number of valence electrons in As

Answer 16

5

Question 17

The term ________ used refers to the idea that a system, which in this case is an arrangement of electrons, does not easily undergo spontaneous change.

Answer 17

stable

Question 18

The valence electron configurations of the ___________ are considered the most stable of all valence electron
configurations.

Answer 18

noble gases

Question 19

gas that is naturally found below the surface of the Earth.

Answer 19

hydrogen gas

Question 20

is the most abundant gas in Earth’s atmosphere, it only makes up 0.005% of Earth’s crust in weight (David Darling).

Answer 20

Nitrogen

Question 21

is essential to human life as our lungs respire oxygen and uses it in metabolism.

Answer 21

Oxygen

Question 22

is the process where carbon compounds are interchanged among the biosphere, geosphere, pedosphere, hydrosphere, and atmosphere of the earth.

Answer 22

Carbon cycle

Question 23

How many protons does krypton has?

Answer 23

36

Question 24

How many protons does iron has?

Answer 24

26

Question 25

How many protons does potassium has?

Answer 25

19

Question 26

How many neutrons does Mercury has?

Answer 26

121

Question 27

How many neutrons does cobalt has?

Answer 27

32

Question 28

How many neutrons does Chlorine has?

Answer 28

19

Question 29

Types of bond

Answer 29

- single bond - double bond - triple bond

Question 30

single bond

Answer 30

Alkanes

Question 31

double bond

Answer 31

Alkenes

Question 32

triple bond

Answer 32

Alkynes

Question 33

When two atoms share one electron pair between each other, then they are said to be bonded by single covalent bond, denoted by single dash joining the atoms.

Answer 33

Single bond

Question 33

When two atoms share two electron pairs between each other, they are said to be bonded by double covalent bond, denoted by double dash joining the atoms.

Answer 33

Double bond

Question 34

When two atoms share three electron pairs with each other, they are said to be bonded by triple covalent bond. Triple bond is denoted by three dashes joining the atoms.

Answer 34

Triple bond

Question 35

it cannot occur, because the last bond can not bend all the way around

Answer 35

Quadruple Bond

Question 36

The _________ concept has its origins in the fact that the nuclei of various elements have differing abilities to attract shared electrons (in a bond) to themselves.

Answer 36

electronegativity

Question 37

_____________ whose contributions to chemical bonding theory earned him a Nobel Prize in chemistry, was the first chemist to develop a numerical scale of electronegativity.

Answer 37

Linus Pauling,

Question 38

A ________________ bond is a covalent bond in which there is equal sharing of electrons between two atoms.

Answer 38

nonpolar covalent bond

Question 39

is a measure of the degree of inequality in the sharing of electrons between two atoms in a chemical bond.

Answer 39

Bond polarity

Question 39

A ________________bond is a covalent bond in which there is unequal sharing of electrons between two atoms.

Answer 39

polar covalent bond

Question 40

In ___________ bond represent in H2 (H-H)

Answer 40

nonpolar covalent bond

Question 41

In ___________ bond represent in HCl (H-Cl)

Answer 41

polar covalent bond