Semestre 2

Question 1

Chemical bond

Answer 1

A force that holds two or more atoms together in a compound, when two atoms share one or more pairs of valence electrons.

Question 2

Atomic number

Answer 2

The number of protons that the atoms has.

Question 3

Electron movement

Answer 3

An electron moves into energy levels, depending on the distance they are closer or farther from neutrons.

Question 4

Energy levels (electron).

Answer 4

2-8-18-32-32-18-8-2

Question 5

Families

Answer 5

7 groups

18 columns

Question 6

Valence electrons

Answer 6

The number of electrons that you need to form a chemical bond.

Question 7

Double covalent bond

Answer 7

When two atoms share two pairs of valence electrons.

Question 8

Triple covalent bond

Answer 8

When two atoms share three pairs of valence electrons.

Question 9

Covalent compounds

Answer 9

When two or more atoms share valence electrons to form a stable compound.

Question 10

Characteristics of the covalent compounds

Answer 10

• Low melting and boring points.
• Usually gas or liquid (can be solid).
• Poor conductors of thermal energy and electricity.

Question 11

Molecule

Answer 11

A group of atoms that are held together by a covalent bond, to act as an independent unit.

Question 12

Polar molecule

Answer 12

Same quantity of protons and neutrons attracted by the charges in their poles (ex. water).

Question 13

Independent unit

Answer 13

Group of atoms with their own chemical and physical characteristics.

Question 14

Chemical formula

Answer 14

Group of symbols and numbers that represent an element in a compound.

Question 15

Compound

Answer 15

Chemical combination of different kinds of atoms.

Question 16

Ion

Answer 16

Atom that is no longer neutral, it has lost or gained a valence electron.

Question 17

Neutral atoms

Answer 17

When it has the same number of protons and electrons.

Question 18

Ionic bond

Answer 18

Attraction between positive and negative charged ions in and ionic compound.

Question 19

Metallic bond

Answer 19

A bond formed when many metal atoms share their pooled valence electron.

Question 20

Metal characteristics

Answer 20

• Shiny.
• Good conductor of thermal energy.
• Ductile - can be stretched into wire.
• Malleable - can be beaten into thin sheets.

Question 21

Non-Metal characteristics

Answer 21

• Poor conductors of heat and electricity.
• Non-ductile.
• Do not possess metallic luster.
• Low density.

Question 22

Covalent bond

Answer 22

• Gas, liquid or solid.
• Low melting and boiling points.
• Poor conductors.
• Dull appearance.

Question 23

Ionic bond characteristics

Answer 23

• Solid crystals.
• High melting and boiling points.
• Poor conductors.

Question 24

Metallic bond characteristics

Answer 24

• Usually solid.
• High melting and boiling points.
• Good conductors.
• Shiny surface.
• Can be easily pulled into wires.

Question 25

Binary compounds

Answer 25

Composed of two elements:

• Metal and non-metal.
• Two non-metals.

Question 26

Binary ionic compound

Answer 26

Contain cation and anion, metal (loses electrons) + nonmetal (gains electrons) = ions.

Question 27

Type compounds

Answer 27

1. One type of cation. (metal)

2. Two or more cations with different charges. (metal)

Question 28

Hallogen

Answer 28

A element located in Group VIIA of the periodic table . Halogens are reactive nonmetals having deben valence electrons.