Topic 2-Bonding,structure and properties of matter.

Question 1

what are the three types of bonding?

Answer 1

->covalent
->ionic
->metallic

Question 2

what is an ion?

Answer 2

An ion is a charged atom.

Question 3

why do atoms lose/gain electrons to form ions?

Answer 3

They are trying to get a full outer shell to become stable.

Question 4

when metals form ions they lose electrons(from outer shell)to form …….

Answer 4

positive ions

Question 5

when non-metals from ions they gain electrons(into outer shell) to form….

Answer 5

negative ions

Question 6

what are positive ions called?

Answer 6

cations

Question 7

what are negative ions called?

Answer 7

anions

Question 8

Describe ionic bonding

Answer 8

->When a metal atom reacts with a non-metal atom electrons in the outer shell of the metal atom are transferred.
-> Metal atoms lose electrons to become positively charged ions. ——>Non-metal atoms gain electrons to become negatively charged ions.
->These oppositely charged ions are strongly attracted to one another by electrostatic forces.

Question 9

Describe a giant ionic lattice

Answer 9

->giant ionic compounds have regular structures
->in which there are strong electrostatic forces in all directions
->between oppositley charged ions
->in the lattice

Question 10

Do ionic compounds have high or low melting/boiling points?

Answer 10

->All have very high melting/boiling points
->due to the many strong bonds between ions
->takes a lot of energy to overcome
->the strong electrostatic forces of attraction

Question 11

why can’t ionic compounds conduct electricity as solids?

Answer 11

->a solid ionic compound
->can not conduct electricity
->ions are held in fixed positions in the lattice
->so ions cannot move around to carry the charge.

Question 12

Why can an ionic compound conduct electricity as a liquid?

Answer 12

->the ions are free to move
->allowing an electrical current to form
->to carry the charge

Question 13

why can an ionic compound conduct electiricty in a solution?

Answer 13

->water molecules seperate ions from the lattice
->the ions are free to move
->allowing an electrical current to form
->to carry the charge

Question 14

Name the advantages/disadvantages of dot and cross diagrams

Answer 14

advantages:
->can show the transfer of electrons
->indicates from which atom the bnding electrons come from
disadvantages:
->does not show the 3D arrangements of the atoms/electron shells
->Does not show the relative sizes of the atoms

Question 15

Name the advantages/disadvantages of the ball and stick model

Answer 15

advantages:
->can show the arrangement of atoms in 3D space
->can help to visualize the shape of the molecule
disadvantages:
->can not show the movement of electrons
->The atoms are placed far apart form each other but in reality the gaps between atoms are much smaller

Question 16

Name the advantages/disadvantages of 2D representations of molecules

Answer 16

advantages:
->displayed formulae are 2d representations of the ball and stick modela nd is simpler.
->shows the bonds of atoms in a molecule
disadvanatges:
->does not show the relative sizesof the atoms and the bonds
->does not show the shape of the molecule in 3D space

Question 17

Name the advantages/disadvantages of 3D represnations of molecules

Answer 17

advantages:
-> Drawing depicts the arrangement in space of the ions
->shows the repeating pattern in giant lattice structures
disadvantages:
->only shows the outermost layer of compound
->are difficult/time consuming to draw.

Question 18

Work out the empirircal formula of potassium oxide

Answer 18

K20

Question 25

why does an atom have no overall charge?

Answer 25

Same number of positively charged protons and negatively charged electrons so the charges cancel each other out.

Question 26

Explain how and why atoms of group 1 and 7 elements react with each other in terms if their electronic structures.

Answer 26

->atoms of Group 1 lose the single electron from outermost shell, ->transferring it to a Group 7 atom, ->which has 7 electrons in its outermost shell, ->both atoms become ions with the stable electronic arrangements of a noble gas