Structure And Bonding

Question 0

What happens when two or more elements react together?

Answer 0

Compounds are formed

Question 1

How do elements react to form compounds?

Answer 1

By gaining or losing electrons, or by sharing electrons

Question 2

What do atoms of elements do to achieve stable electronic structures?

Answer 2

The atoms of elements join together by sharing electrons or by transferring electrons. Atoms of the noble gases have stable electronic structures

Question 3

What is it called when non-metallic elements join together by sharing electrons?

Answer 3

Covalent bonding

Question 4

What happens when metallic elements react with non-metallic elements?

Answer 4

They produce ionic compounds

Question 5

What do metal atoms form after losing electrons?

Answer 5

Positive ions

Question 6

What do the atoms of non metals form after gaining electrons?

Answer 6

Negative ions

Question 7

What is ionic bonding?

Answer 7

Oppositely charged ions attracting each other in the ionic compound

Question 8

How many electrons are in the outer shell of an atom in Group 1? Give an example of a Group 1 atom.

Answer 8

1 electron in the outer shell of a Group 1 atom. An example of a Group 1 atom is sodium (Na)

Question 9

How are ionic compounds held together?

Answer 9

Strong forces between oppositely charged ions. This is called ionic bonding.

Question 10

What do the ions form and how are the strong forces of attraction involved?

Answer 10

The ions form a giant structure or lattice. The strong forces of attraction act throughout the lattice.

Question 11

How can we represent atoms and ions in a diagram?

Answer 11

Dot and cross diagram

Question 12

Ionic bonding holds oppositely charged ions together in WHAT?

Answer 12

Giant structures

Question 13

Why is the giant structure of ionic compounds regular?

Answer 13

The ions all pack together neatly, like marbles in a box

Question 14

Strong electrostatic forces of attraction act in WHICH direction?

Answer 14

All directions

Question 15

What is each ion in the giant structure or lattice is surrounded by and what does it ensure?

Answer 15

Ions with an opposite charge so it is held firmly in place

Question 16

The sodium and chloride ions alternate to form a WHAT?

Answer 16

A cubic lattice

Question 17

The ratio of ions in a structure of an ionic compound depends on WHAT? Give an example.

Answer 17

The charge of the ions. For example, calcium ions are Ca2+ and chloride ions are Cl-, so calcium chloride contains twice as many chloride ions as calcium ions and it’s formula is CaCl2.

Question 36

What is the charge of ionic compounds?

Answer 36

Neutral

Question 37

What do the charges on the ions always do?

Answer 37

The charges on the ions in an ionic compound always cancel each other out

Question 38

What does the formula of an ionic compound show?

Answer 38

Th ratio of ions present in the compound

Question 39

When is a covalent bond formed?

Answer 39

When 2 atoms share a pair of electrons

Question 40

What does the number of covalent bonds that an atom forms depend on?

Answer 40

The number of electrons it needs to achieve a stable electronic structure

Question 41

How are atoms in metals arranged?

Answer 41

Closely packed together and arranged in regular layers

Question 42

What happens to the electrons of a metal atom in the highest energy level?

Answer 42

The electrons are delocalised

Question 43

What holds the metal atom together?

Answer 43

The strong electrostatic forces between the electrons and the positively charged metal ions.

Question 44

Are the atoms in a metallic element all the same size or do they differ?

Answer 44

All the same size

Question 45

What does it mean if the electrons in the highest energy level delocalise?

Answer 45

The electrons can move freely between atoms

Question 46

When electrons in the highest energy level delocalise and can move between atoms freely, what is produced?

Answer 46

A lattice of positive ions in a 'sea' of moving electrons.

Question 47

What do the delocalised electrons do?

Answer 47

Attract the positive ions and hold the giant structure together

Question 48

What is a compound?

Answer 48

A substance made of two or more elements that have reacted together or that are chemically bonded together

Question 49

Which elements in an atom are involved in bonding?

Answer 49

The outer electrons

Question 50

What happens to electrons in atoms when ionic bonds are formed?

Answer 50

The are transferred or metal atoms old electrons and non metal atoms gain electrons

Question 51

What happens to electrons in atoms when covalent bonds are formed?

Answer 51

They are shared. For each covalent bond, one pair of electrons is shared

Question 52

Why do the elements in Group 1 form ions with a single positive charge?

Answer 52

They lose their one outer electron

Question 53

Why do the elements in Group 7 form ions with a single negative charge?

Answer 53

They gain one electron so their outer shell has 8 electrons or so they have the structure of a noble gas

Question 54

Why can the structure of a metallic element like copper be represented by lots of small spheres the same size packed together?

Answer 54

The atoms in copper are all the same size, they are spherical, they are closely packed together in a giant structure

Question 55

Why do ionic compounds have giant structures?

Answer 55

The attractive forces between oppositely charged ions in all directions, so the ions pack closely together in a regular arrangement (lattice), ions are very small so a crystal contains many ions

Question 56

Explain why silicon (Group 4) has a giant structure.

Answer 56

Silicon atoms form 4 covalent bonds, each silicon atom can join to 4 others, the bonds are strong; this continues so that a giant structure is formed

Question 57

Explain how atoms in a piece of sodium metal are held together

Answer 57

The outer electrons delocalise, leaving a lattice of positive ions; the delocalised electrons attract positive ions; the electrostatic forces are strong, and these hold the ions in position