semester one exam

Question 1

three parts of an atom

Answer 1

protons, neutrons, electrons

Question 2

what charge do protons have

Answer 2

positive

Question 3

what charge do neutrons have

Answer 3

neutral

Question 4

what charge do elcetrons have

Answer 4

negative

Question 5

define an element

Answer 5

a pure substance made up of atoms of the same type. there are 92 naturally occuring elements

Question 6

define a compound

Answer 6

two or more elements chemically combined. cannot be easily separated

Question 7

electron configuration of first 4 shells

Answer 7

2n^2
first shell: 2
second shell:8
third shell:18
fourth shell:32

Question 8

how many electrons can the outer most shell have

Answer 8

8,, after 8 electrons fill the outer shell a new shell starts and then once that one reaches 8 it goes back and fills the other shell

Question 9

atomic radius increases when

Answer 9

you move down the periodic table

Question 10

atomic radius decreases when

Answer 10

you move across the periodic table

Question 11

ionic compounds

Answer 11

metals - nonmetals

Question 12

covalent bonding

Answer 12

nonmetals - nonmetals

Question 13

metalic bonding

Answer 13

metals-metals

Question 14

cations

Answer 14

positive ions, generally metals, lose electrons to become positively charged with noble gas configuration

Question 15

anions

Answer 15

negative ions, generally nonmetals, gain electrons to become negatively charged with noble gas configuration

Question 16

balanced chemical equations and lewis structure

Answer 16

how you write chemical equations

Question 17

4 observations that show a chemical reactions

Answer 17

change in temperature
change in colour
formation of a precipitate
light or sound given off

Question 18

4 steps to a writting a balanced chemical equation

Answer 18

worded equation
chemical formulas
balance it using big numbers
add subscripts of states of reactants and product

Question 19

particles that determine elements place in periodic table

Answer 19

protons and electrons

Question 20

noble gases

Answer 20

have full outer shells and are stable

Question 21

(aq)

Answer 21

aquius solution, elements or compounds disolved in water or solution

Question 22

increaing surface area to volume ratio does

Answer 22

it exposes more area of the reactants to increase speed of reaction because more room for reaction to take place

Question 23

combustion reactions

Answer 23

when methane, petrol or pentane (hydrocarbons) and oxygen react to form carbon dioxide and water

Question 24

precipitation reaction

Answer 24

when two ionic aquius solutions combined react and form a precipitate

Question 25

decompositon reaction

Answer 25

when a substance is brocken down using heat into simpler forms
CaCO3–>CaO + CO2

Question 26

displacement reaction

Answer 26

when a metal is added to a ionic aquius solution and the stronger metal displaces the weaker metal out of solution

Question 27

endothermic reaction

Answer 27

when a reaction loses heat as it takes in heat from the surroundings

Question 28

exothermic reaction

Answer 28

when a reaction produces heat and the temperature of the reaction rises

Question 29

factors that increase the rate of reaction

Answer 29

surface area to volume ratio
concentration
temperature

Question 30

SI unit

Answer 30

m-meters
kg-kilograms
s-seconds
K-kelvins
N-newtons
m/s-meters per second
m/s/s-meters per seond per second

Question 31

average speed

Answer 31

speed=distance/time

Question 32

kelvins to celcius

Answer 32

+273

Question 33

scalar values

Answer 33

have size such as distance

Question 34

vector values

Answer 34

have both size and direction such as velocity. must give a direction

Question 35

ticker timer

Answer 35

50 spaces/dots = 1 second

Question 36

acceleration due to gravity

Answer 36

9.8m/s

Question 37

acceleration

Answer 37

acceleration = final velocity-intial velocity/time

Question 38

a precipitate is

Answer 38

a solid forming from a chemical reaction, changing the colour

Question 39

force

Answer 39

force = mass x acceleration

Question 40

m/s –> km/h

Answer 40

x 3.6

Question 41

km/h –> m/s

Answer 41

divided by (/) 3.6

Question 42

newtons first law

Answer 42

INERTIA- an objects tendency to resist changes in motion. so keep moving until something stops it or stay still until a force makes it move

Question 43

newtons first law example

Answer 43

when a train breaks and you continue to move and fall over

Question 44

newtons second law

Answer 44

force=mass x acceleration. an object will accelerate in the direction of an unbalance force (larger force) acting upon it. the size of the acceleration depends on the mass of the object and the size of the force acting on it.

Question 45

newtons second law example

Answer 45

force = 60 x 9.8 = 588N. my total force when falling on earth

Question 46

newtons third law

Answer 46

for every action force there is an equal and opposite reaction force. forces occur in pairs

Question 47

newtons third law example

Answer 47

when a rocket takes of it pushes gases out (action force) which causes the gas to push the rocket up (reaction force).