2. Inside the Atom: Structure, Valency, and Bonds

Question 1

Two types of compounds

Answer 1

Ionic and Covalent (molecular)

Question 2

What is metal+non metal bonding?

Answer 2

Ionic bonding

Metals loose electrons and non metals gain electrons

Question 3

Properties of Ionic compounds

Answer 3

Physical
High melting and boiling points (strong electrostatic forces)
Conduct electricity when molten or dissolved (free-moving ions)

Chemical
A more reactive metal can displace a less reactive metal from its ionic compound
Usually soluble in water (many form aqueous solutions)

Question 4

What is molecular/ covalent bonding?

Answer 4

Between 2 nonmetals

Share electrons

Question 5

What is polar- covalent bonding?

Answer 5

Unequal sharing of electrons between atoms

Question 6

List 4 properties of (covalent) molecular bonding

Answer 6

1. Bad conductor of electricity
2. Low m.p. and b.p.
3. Do not dissolve in water
4. Dissolve in organic solvent (ethanol)

Question 7

What are isotopes?

Answer 7

Same number of protons different number of neutrons

Question 8

How many protons in an element?

Answer 8

Equal to Atomic Number

Question 9

How many neutrons?

Answer 9

Atomic mass- Atomic Number

Question 10

What is Metallic Bonding

Answer 10

Bonding in metals.

Metals loose electrons to form a giant sea of electrons around them. These electrons are tightly packed in the lattice

Question 11

What are the electrons which are lost from metals known as?

Answer 11

Delocalised Electrons

Question 12

Properties of Metals

Answer 12

Physical Properties:
Malleable and ductile – can be shaped or stretched without breaking
Good conductors of heat and electricity – due to free-moving electrons

Chemical Properties:
React with acids to produce a salt and hydrogen gas
Form positive ions (cations) in reactions – they lose electrons

Question 13

What is an addition of 2 or more metals known as?
How is the strength compared to regular metals?

Answer 13

Alloy
Since atoms added are larger, alloys are stronger than metals, they are also less malleable and ductile.

Question 14

Give 3 examples of covalent molecular structures

Answer 14

CO2, H2O, Br2, S8

Question 14

What are covalent molecular structures?

Answer 14

Small molecules, strong covalent bonds within molecules, weak between molecules.

Question 15

What is a covalent network?

Answer 15

Giant repeating lattices of lot of covalently bonded atoms

Question 16

What is the term for different forms of the same element?

Answer 16

Allotropes

Question 16

3 properties of allotropes

Answer 16

1. Brittle
2. High m.p.
3. Non- conductor (except graphite)

Question 17

Two examples of Allotropes of Carbon

Answer 17

Diamond and Graphite

Question 18

How many free electrons does carbon have?

Answer 18

ZERO

Question 18

How many free electrons does graphite have?

Answer 18

ONE

Question 19

Collision theory

Answer 19

More frequent reactions, increase particle speed, more particles present- more successful collisions

Question 20

To calculate rate of reaction

Answer 20

Amount of mass lost/ time or amount of product formed/time

Question 21

5 factors affecting rate of reaction

Answer 21

1. Temperature
2. Pressure
3. Concentration of solution
4. Surface Area of solids
   5.Catalyst

Question 22

Properties of Isotopes

Answer 22

Physical Properties Different mass numbers – because they have different numbers of neutrons Different densities or boiling/melting points – due to the mass difference Chemical Properties Same electron configuration to react the same way Form same compounds – they behave identically in chemical reactions

Question 22

Properties of Metalloids

Answer 22

Physical Properties Brittle – they break easily when hit, like non-metals Metallic Luster – they often look shiny like metals Chemical Properties Amphoteric behavior – They can act like metals or non-metals depending on the reaction Form both ionic and covalent compounds – they bond with metals and non-metals