Unit 1 Chemical Changes + Structure

Question 1

what is an element?

Answer 1

an element is a substance that consists of only one type of atom

Question 2

True or False everything in the world is made up of just over 97 elements

Answer 2

False everything in the world is made up of just over 100 elements

Question 3

what is the periodic table?

Answer 3

The periodic table is the arrangement of all known elements

Question 4

What are most elements?

Answer 4

solids

Question 5

true or false only 2 elements in the periodic table are liquids

Answer 5

true

Question 6

true or false many of the non metal elements are solids

Answer 6

false most of them are gases

Question 7

what are the vertical columns of the periodic table called?

Answer 7

groups

Question 8

What are the horizontal rows on the periodic table called?

Answer 8

periods

Question 9

what are the groups numbered as?

Answer 9

1-7 but the last group is either 8/0

Question 10

what do all the different groups have?

Answer 10

They all have different chemical properties e.g.** group 1 is very reactive** with sodium and potassium having very violent reactions

Question 11

true or false an element only contains 1 type of atom

Answer 11

true

Question 12

what is a chemical symbol?

Answer 12

A chemical symbol is a short hand way of representing an element. Each element had its own chemical symbol.

Question 13

what does a modern chemical symbol look like?

Answer 13

They consist of one or two letters. The first one is a capital letter but the second one (if it has one) is lower case. e.g H - Hydrogen or Fe - Iron

Question 14

how many electrons does group 1 have on its outermost shell

Answer 14

the group 1 elements all have 1 outer electron. its teh sma efor all of the groups

Question 15

true or false group 1 is very reactive

Answer 15

true

Question 16

true or false group 7 is not very reactive

Answer 16

false group 7 is very reactive

Question 17

true or false group 2 is normal reactive

Answer 17

true

Question 18

true or false group 8/0 is the most reactive

Answer 18

false group 8/0 is not reactive

Question 19

what is a mixture?

Answer 19

when two or more elemnts are jumbled together but dont chemically join

Question 20

what is a compound?

Answer 20

In a compound, two or more elements are chemically joined. They are held by very strong bonds and cannot be easily seperated back into their elements.

Question 21

what is a solution?

Answer 21

a mixture formed when a solute dissolves in a solvent.

Question 22

what is a solute?

Answer 22

the substance that dissolves in the solvent

Question 23

what is a solvent?

Answer 23

the substance which other substances dissolve in.

Question 24

what does it mean if a substance is soluble?

Answer 24

a substance that can dissolve

Question 25

what is a dilute solution

Answer 25

a small amount solutedissolved in solvent

Question 26

what is a saturated solution?

Answer 26

when the maximum amount of solute has been dissolved in the solvent.

Question 27

what is a state symbol

Answer 27

the state symbol is a superscript in brackets following the name of the substance

Question 28

whats the state symbol for solids?

Answer 28

(s)

Question 29

whats the state symbol for liquids?

Answer 29

(l)

Question 30

whats the state symbol for gas?

Answer 30

(g)

Question 31

what the state symbol for a solute dissolved in water?

Answer 31

(aq)

Question 32

what always happens in a chemical reaction?

Answer 32

A new substance is produced. There will also always be signs for a new substance being produced.

Question 33

How many elements are in an -ide compound?

Answer 33

2 elements

Question 34

true or false compounds that contain 2 elements + oxygen end in xyz

Answer 34

false they end in -ite or -ate

Question 35

what would iron sulphide be made of?

Answer 35

iron+ sulphate

Question 36

what would zinc carbonate be made of?

Answer 36

zinc+carbon+oxygen

Question 37

what would alumininum sulphite be made of?

Answer 37

aluminium+sulphur+oxygen

Question 38

true or false hydroxide means made of hydrogen and oxygen

Answer 38

true e.g sodium hydroxide = sodium+hydrogen+oxygen

Question 39

what is a rate of a chemical reaction?

Answer 39

how fast the reaction happens

Question 40

what must happen for a chemical reaction?

Answer 40

the particles must collide with energy and the correct allignment

Question 41

what does it mean if the particle size decreases

Answer 41

the rate of reaction increases as there is more surface area for particles to collide e.g calcium carbonate powder reacts faster than calcium carbonate lumps

Question 42

what does it mean if the particle size increases

Answer 42

the rate of reaction decreases as there is less surface area for particles to collide

Question 43

what happens to the reaction rate as temperature is increased?

Answer 43

when the temperature is increased the particles move faster - there are more collisions => faster reaction rate

Question 44

what is an exothermic reaction?

Answer 44

an exothermic reation is a reaction that releases enegergy in the form of heat.

Question 45

what is an endothermic reaction

Answer 45

an endothermic reaction absorbs (takes in energy) .

Question 46

what are some of the signs of a chemical reaction?

Answer 46

- colour change - gas given off (smell or fizzing) - changing temperature

Question 47

what happens to the rate of reaction when there is a lower concentration?

Answer 47

The reaction rate is slower as there are less particles => less collisions

Question 48

what happens to the reaction rate when there is a higher concentration?

Answer 48

The reaction rate is quicker as there are more particles => more collisions

Question 49

What effects the rate of reaction?

Answer 49

- temperature - particle size - concentration - catalyst

Question 50

what are the two types of catalyst?

Answer 50

hetrogenous and homogenous

Question 51

what is a hetrogenous catalyst?

Answer 51

a hetrogenous catalyst is one which has a different physical state to the reactants e.g solids and liquids etc

Question 52

what is a homogenous catalyst?

Answer 52

a homogenous catalyst is aone which has the same physical state to the reactants

Question 53

what is a catalyst

Answer 53

Catalysts are substances which speed up a chemical reaction without being used up in the process

Question 54

what is an enzyme?

Answer 54

Enzymes are biological catalysts i.e they exist in living things and reaction happen in them

Question 55

do all enzymes work?

Answer 55

some do and some don't

Question 56

True or False enzymes are highly specific to which they catalyse

Answer 56

true a suitable enzyme must be used for an appropriate reaction

Question 57

If there is an increase in particle size

Answer 57

reaction rate decreases

Question 58

if there is a decrease in particle size

Answer 58

reaction rate increases

Question 59

increase in concentration

Answer 59

reaction rate increases

Question 60

decrease in concentration

Answer 60

reaction rate decreases

Question 61

increase in temperature

Answer 61

reaction rate increase

Question 62

decrease in temperature

Answer 62

decrease in reaction rate

Question 63

add a catalyst

Answer 63

reaction rate increases

Question 64

What can the progress of a chemical reation be followed by?

Answer 64

measuring the change in -mass -volume -concentration