Topic 2 - Structure And Bonding

Question 0

The electrons

Answer 0

1. they are tiny but cover a lot of space
2. have virtually no mass
3. occupy shells around the nucleus
4. charge -1
5. mass 1

Question 1

The nucleus

Answer 1

1. almost whole mass of the atom
2. is tiny compared to the whole atom

Question 2

How does Ionic Bonding happen?

Answer 2

1. Ionic bonds form between metals and non-metals
2. Metal atoms lose electrons to form positive ions (cations)
3. Non-metals gain electrons to form negative ions (anions)
4. The oppositely charged ions attract one another (electrostatic attraction)
5. Strong electrostatic attraction between oppositely charged ions

Question 3

Giant ionic structure

Answer 3

1. The ionic bond is the strong electrostatic attraction between the positive and negative ions next to each other in the lattice
2. The bonds extends through the crystals in all directions
3. The alternate positive and negative ions in a ionic solid are arranged in an orderly way in a giant ionic lettuce structure

Question 4

Properties of ionic compounds

Answer 4

1. Tend to be hard but shatter
2. Strong bonding force makes the structure hard. They are not malleable like metals-brittle
3. Have high melting and boiling points
4. Many ionic compounds are solliable in water, but not all
5. Solid crystals do not conduct electricity

Question 5

What is oxydation

Answer 5

Loss of electrons

Question 6

What is reduction

Answer 6

Gain of electrons

Question 7

What is Covalent bonding?

Answer 7

• 2 non-metals
• A pair of electrons is shared between 2 atoms
• Each positively charged nuclei is attracted to the same negatively charged pair of electrons
• A strong attraction between the bonding pair of electrons and the nuclei of the atoms involved in the bond

Question 8

Covalent structures

Answer 8

• molecules
• high MP
• weak forces between molecules
• low BP
• giant covalent structure
• strong covalent bond *not conduct-no charged particles

Question 9

Summary of ionic bonding

Answer 9

1. when metals react with non metals they form ionic compounds
2. transfer of electrons
3. metal ions give electrons and are oxidized to form positive ions
4. non metals gain electrons and are reduced to form negative ions
5. the ions are arranged in giant ionic lattices
6. the opposite charged ions are attracted to each other by strong electrostatic forces- ionic bonding

Question 10

What does an atoms consist of?

Answer 10

Central nucleus, composed of protos and neutrons, surrounded by electrons, orbiting in shells.

Question 11

Protons

Answer 11

relative mass: 1

relative charge: +1

Question 12

Neutrons

Answer 12

Relative mass: 1

Relative charge: 0

Question 13

Explain what atomic and mass number means

Answer 13

Atomic number: protons+neutrons

Mass number: protons+neutrons+electrons

Question 14

Explain the term isotope

Answer 14

Any of two or more forms of a chemical element having the same number of protons but different number of neutrons

Question 15

Explain the term Relative atomic mass (Ar/RAM)

Answer 15

the average mass of all isotopes of an element relative to carbon-12.

Question 16

How can you calculate the relative atomic mass from the relative abundances of its isotopes

Answer 16

(% of isotope x mass of isotope) + (% of isotope x mass of isotope) over 100

Question 17

Deduce the electron configuration

Answer 17

Question 18

Deduce the number of outer electrons in a main group element from its position in the periodic table

Answer 18

Question 19

Recall the charges of common ions

Answer 19

Question 20

Deduce the charge of an ion from the electronic configuration of the atom

Answer 20

Question 21

Explain, using dot and cross diagrams, the formation of covalent compounds by electron sharing for water

Answer 21

Question 22

Ionic Compound

Answer 22

They have high melting and boiling points because of strong electrostatic forces between oppositely charged ions

Question 23

Expain, using dot and cross diagrams, the formation of ionic compounds by electron transfer

Answer 23

Question 24

Describe the formation of a covalent bond by the sharing of a pair of electrons between two atoms

Answer 24

• A covalent bond is a strong bond between two non-metal atoms.
• It consists of a shared pair of electrons.
• A covalent bond can be represented by a straight line or dot-and-cross diagram.

Question 25

Explain, using dot and cross diagrams, the formation of covalent compounds by electron sharing for hydrogen

Answer 25

Question 26

Explain, using dot and cross diagrams, the formation of covalent compounds by electron sharing for ethane

Answer 26

Question 27

Which substances are with simple molecular structures?

Answer 27

gases,liquids or solids with low melting points

Question 28

Explain why substances with simple molecular structures have low melting and boiling points in terms of the relatively weak forces between the molecules

Answer 28

• A substance with a simple molecular structure is one that contains only a few atoms in a molecule.
• The intermolecular forces (between the molecules) are weak, so it doesn’t take much energy- or heat- to break them- this means they will melt and boil under low heats, as even small amounts of heat energy are enough to break the bonds.