Unit 3 Flashcards Preview

Chemistry > Unit 3 > Flashcards

Flashcards in Unit 3 Deck (35):
1

Why is an Ion charged

Because it has an unequal number of protons and electrons

2

What groups ionic bonding between

Metals and non-metals

3

What is an ionic bond

Went to ions have opposite charges so they attract each other the force of attraction between them is strong

4

What form positive ions

Hydrogen and metals

5

What do non-metals form

Negative ions and their names end in -ide

6

Why do groups four and five not usually form ions

Because they would have to lose or gain several electrons and that would take too much energy

7

Why does group 0 not form ions

Because they have a full outer shell already

8

What type of metals town form more than one ion

Transition metals

9

What are compound ions

When ions can be formed from groups of joined atoms

10

What are the properties of an ionic compound

Ionic compounds have high melting and boiling points. This is because ionic bonds are very strong, so it takes a lot of heat energy to break up the lattice.
Ionic compounds are usually soluble in water. The water molecules can attract the ions away from the lattice. The ions can then move freely, surrounded by water molecules.
Ionic compounds can conduct electricity when they are melted or dissolved. When melted the lattice breaks up on the ions are free to move. Since they are charged, this means they can conduct electricity. The solutions of ionic compounds conduct electricity to because they are also free to move.

11

What is a lattice?

Ionic lattice structure each positive ion is surrounded by several negative ions

12

What is covalent bonding between?

Nonmetals only since nonmetals need to gain electrons

13

What is a single covalent bond

When a pair of electrons are shared

14

What is a double covalent bond

Two pairs of electrons are shared

15

What is a triple covalent bond

When 3 Pairs of electrons are shared

16

What is A covalent compound

When atoms of different elements share electrons with each other

17

Why are molecules in a covalent bond not flat

Because each electron repel each other and try to get as far apart from each other

18

What are the solids in a molecular substance

Crystaline

19

What happens when you cool down and molecular liquid or gas

The molecules lose energy so they start moving slowly and at the freezing point, they form a lattice

20

What are the properties covalent bonding

Have lower melting and boiling points. This cause the forces between the molecules molecules are weak
Do not conduct electricity. This is because molecules are not charged, so they cannot conduct, even when melted

21

What is a giant covalent structure for a macromolecules

Made of billions of atoms bonded together in a covalent structure

22

Diamond-giant covalent structure

Diamond is made of carbon atoms held in a strong lattice. Each carbon atom forms a covalent bond to four others. Eventually billions of carbon atoms bond together To form a Crystal of diamond

23

What are Diamond Properties

Hard because each atom is held by for strong bonds
It has a very high melting point because of the strong bonds
It can't conduct electricity because there are no free electrons to carry the charge

24

What is similar to diamond

Silica

25

Graphite

Like diamond graphite is made only of carbon atoms. So Diamond is and graphite are allotropes of Carbon (means they are two forms of the same element). Graphite, unlike diamond, is one of the softest solids on Earth. In graphite, each carbon atom forms a covalent bond to 3 others. This gives rings of six atoms

26

What are graphite properties

Soft and slippery because the sheets can slide over each other
It's a good conductor of electricity because each carbon has for outer electrons and graphite bond three only so the four electron is free to move carrying a charge.

27

What are the uses of diamond

Jewellery
For tools for drilling and cutting

28

What are the uses of silica

In sandpaper
For making glass and lenses
In bricks for lining furnaces

29

What are the uses for graphite

As a lubricant for engines
For pencil lead which is mixed with clay
For electrodes and connecting brushes in generators

30

What are the properties of silica

They are hard and can scratch things
Hard .let's light through
High melting point

31

What is a metallic bond

Is the force of attraction between free electrons and metal ions

32

Why do metals have high melting points?

This is because it takes a lot of heat energy to break up the lattice

33

Why metals are malleable and ductile

Malleable-they can be bent and pressed into shapes
Ductile-They can be drawn into wires

This is because the layers can slide without the metallic bond breaking, because the electrons are free to move to

34

Why are metals good conductors of heat

It's because the free electrons take in heat energy, which makes them move faster and they quickly transfers heat through the metal structure

35

Why are metals good conductors of electricity

This is because the free electrons can move through the lattice Carrying the charge