4. chemical bonding

Question 1

what is a gas with full valence shell said to have

Answer 1

noble gas configuration

Question 2

properties of noble gases

Answer 2

-chemically unreactive
-monoatomic (exists as a single atom)

Question 3

3 ways atoms chemically combine to achieve complete valence

Answer 3

-loss of electrons
-gain of electrons
-sharing of electrons

Question 4

positive ions are also known as

Answer 4

cations

Question 5

cations are also known as

Answer 5

positive ions

Question 6

characteristics of positive ions

Answer 6

positive ions (cations) have a net positive charge and usually have a noble gas electronic configuration

Question 7

negative ions are also known as

Answer 7

anions

Question 8

anions are also known as

Answer 8

negative ions

Question 9

characteristics of negative ions (anions)

Answer 9

negative ions (anions) have a net negative charge and have a noble gas electronic configuration

Question 10

what is the ionic bond

Answer 10

the mutual electrostatic attraction between ions of opposite charges

Question 11

What is an ionic compound?

Answer 11

A neutral substance that consists of ions of opposite charges held together by ionic bonds.

Question 12

What types of atoms typically form positive ions?

Answer 12

Metal atoms.

Question 13

What types of atoms typically form negative ions?

Answer 13

Non-metal atoms.

Question 14

when is the charge balanced in ionic compounds?

Answer 14

The total positive charge from positive ions must equal the total negative charge from negative ions.

Question 15

What is the ratio of sodium ions to chloride ions in sodium chloride?

Answer 15

1:1.

Question 16

What is the formula for sodium chloride?

Answer 16

NaCl.

Question 17

True or False: Ionic compounds have a net charge.

Answer 17

False.

Question 18

Fill in the blank: Ionic bonds are formed by _______ between positive and negative ions.

Answer 18

electrostatic forces of attraction.

Question 19

What is the total positive charge of a sodium ion?

Answer 19

+1.

Question 20

What is the total negative charge of a chloride ion?

Answer 20

-1.

Question 21

describe the ionic structure

Answer 21

a giant ionic crystal lattice
( a three dimensional structure of alternating positive and negative ions )

Question 22

valency

Answer 22

valency refers to the number of electrons that must be lost, gained or shared in order for the atom to attain noble gas electronic configuration

Question 23

what is covalent bonding

Answer 23

covalent bonding is the result of the sharing of electrons between non metal atoms in order to achieve a noble gas configuration

Question 24

what can covalent molecules be formed of

Answer 24

a covalent molecule can be made from atoms of the same or different elements

Question 25

describe a simple molecule

Answer 25

they have a countable number of atoms in a fixed ratio

Question 26

example of simple molecules

Answer 26

- water (1 oxygen atom and 2 hydrogen atoms) - wax molecule (18 carbon atoms and 38 hydrogen atoms)

Question 26

describe a giant molecule

Answer 26

giant molecules have a practically uncountable number of atoms in each molecule

Question 26

example of giant molecules

Answer 26

- diamond (1g contains about 5.02x10^22) -a grain of sand (mostly silicone dioxide) (made up of as many as 6.02x10^22 silicon atoms and 1.2x10^21 oxygen atoms)

Question 27

what are metal atoms held together by

Answer 27

metallic bonding

Question 27

why do metals not combine using ionic or covalent bonding

Answer 27

metals can only form simple positive ions (not negative ions) thus ionic bonding between metals is unlikely to happen

Question 28

the metallic bond

Answer 28

the metallic bond is the mutual electrostatic attraction between positively charged ions in a metal and the ‘sea of delocalised electrons’

Question 29

structure of metals in metallic bonding

Answer 29

solid metals have a giant metallic lattice structure held together by positive ions in a ‘sea of delocalised electrons’