chemistry 901 - 905

Question 1

what groups are transition metals?

Answer 1

group 2-13

Question 2

what are group 18 elements called

Answer 2

inert gases/noble gases

Question 3

name the group one elemets

Answer 3

lithium, sodium, potassium, rubidium, caesium, francium

Question 4

group 1 element properties

Answer 4

metals
silvery surface
reactive
easily oxidized
light metals that float in water
soft
low melting and boiling points

Question 5

describe brownian movement

Answer 5

random movement of particles which are suspended in liquid/gas and result in collisions

Question 6

state the kinetic theory of matter

Answer 6

1)all states of matter are made of particles that in constant motion, solids vibrate, liquids move into empty spaces and gases move freely

Question 7

define gas pressure

Answer 7

pressure caused by collisions (P+F/A)

Question 8

state atomic theory

Answer 8

all matter is made of atoms, atoms
atoms cannot be created nor destroyed
divisible into protons, electrons, and neutrons

Question 9

define nucleon number

Answer 9

number of neutrons + protons

Question 10

the five types of reactions

Answer 10

1) metal + water —-> metal hydroxide + hydrogen gas
2) acid + base —-> salt + water
3) metal + acid —-> salt + hydrogen gas
4) metal oxide + acid —–>salt + water
5) metal carbonate + acid ———> salt + carbon dioxide + water

Question 11

group 17 elements

Answer 11

fluorine, chloride, bromine, iodine, astatine

Question 12

characteristics of group 17

Answer 12

1) non-metals
2) reactive
3) diatomic (made out of 2 atoms)
4) highly electronegative
5) has 7 valance electrons
6) low melting and boiling points
7) bad conductors
8) low density

Question 13

group 18 elements

Answer 13

helium, neon, argon, krypton, xenon, and radon

Question 14

noble gases characteristics

Answer 14

1) bad conductors
2) insoluble in water
3) inert/inactive because they have 8 valance electrons
4) colourless,tasteless,odourless
5) low boiling points

Question 15

range of transition metals

Answer 15

group 2-13(not including 2)

Question 16

properties of the first period of transition elements

Answer 16

1) metals
2) high melting and boiling points
3) solids with shiny surfaces
4) malleable and ductile
5) high tensile strength
6) high densities
7) good conductors of heat and electricity

Question 17

special characteristics of transition metals

Answer 17

1) they form colored ions
2) charge of the ions formed from transition elements are variable
3) forms complex ions
4) acts as catalysts

Question 18

describe Harber process

Answer 18

manufacturing of ammonia from the reaction between nitrogen and hydrogen using iron as a catalyst

Question 19

describe contact process

Answer 19

in manufacturing of sulphur acid sulphur dioxide reacts with oxygen to form sulphur trioxide, using vanadium as a catalyst

Question 20

use of transition elements

Answer 20

• added to paints and glass
• used for radiators and for electrical wires
• as catalysts in industrial processes

Question 21

why do elements form compounds rather than remain in element form?

Answer 21

because they are more stable in compound form

Question 22

difference between ionic bond and covalent

Answer 22

ionic bond -(1) by loss/gain of electrons
(2) between metals and non metals
(3)forms positive and negative ions
(4)strong electrostatic forces
covalent bonds - (1)by sharing electrons
(2)sharing between non metals only 
(3)forms electrically neutral molecules
(4)weak Van der Waal's forces

Question 23

property differences between ionic and covalent compounds

Answer 23

ionic - (1) high melting and boiling point
(2)soluble in water/insoluble in organic solvents
(3)can conduct electricity in aqueous state
(4)not easily evapurated(solids)
covalent - (1)low melting and boiling
(2)insoluble in water/soluble in organic solvents
(3)can conduct electricity in any state (except graphite)
(4)easily evaporated(any state)

Question 24

define chemical formula

Answer 24

chemical formula is a chemical representation of substances using letters, subscript numbers which represent the number of atoms combined together to form the substance

Question 25

define valency of an element

Answer 25

teh valency refers to how many electrons need to be gained/lost/shared for a compound to be formed

Question 26

law of conservation of mass

Answer 26

matter can neither be created nor destroyed. It can only change from one form to another

Question 27

define relative atomic mass

Answer 27

RAM is the number of times one atom of a substance is heavier than one atom of carbon -12

Question 28

define relative molecular mass

Answer 28

number of times which one molecule of a substance is heavier than one molecule of carbon -12

Question 29

formula for purity

Answer 29

(mass of pure substance/total mass) x 100

Question 30

how much is one mole?

Answer 30

6.02 x 10^23(Avogado’s constant)