Topic 1: atomic structure and the periodic table

Question 1

what is an atom

Answer 1

the smallest part of an element that can exist

Question 2

what is an element

Answer 2

a substance made up one type of element only

Question 3

how are the elements listed

Answer 3

periodic table

Question 4

how many elements approx

Answer 4

100

Question 5

elements can be classified into two groups based on properties, what are they

Answer 5

metals and non-metals

Question 6

elements may combine through chemical reactions to form new products, what are the new products called

Answer 6

compounds

Question 7

what is a compound

Answer 7

two or more elements combined chemically in fixed proportions which can be represented by formulae

Question 8

do compounds have the same properties as their constituent elements

Answer 8

no - have different properties

Question 9

what is a mixture

Answer 9

consists of two or more elements not chemically combined together

Question 10

do mixtures have the same chemical properties as its constituent materials

Answer 10

yes, they have the same chemical properties

Question 11

what are the methods mixtures can be separated

Answer 11

filtration
crystallisation
simple distillation
fractional distillation
chromatography

Question 12

do methods separating mixtures involve chemical reactions

Answer 12

no they do not

Question 13

what is simple distillation used for

Answer 13

simple distillation is used to separate liquids from a solution

Question 14

explain simple distillation

Answer 14

the liquid boils off and condenses in the condenser
the thermometer will read the boiling point of the pure liquid

Question 15

what is crystallisation?

Answer 15

the process of formation of solid crystals from solution, melt or by deposition directly from a gas phase.

Question 16

explain crystallisation?

Answer 16

removing some of the solvent by evaporation to form a saturated solution. then cool down the solution. as its done, you do this the solid starts to crystallise, and less soluble at lower temperatures. the crystals can be collected and separated from the solvent via filtration

Question 17

what is evaporation

Answer 17

technique for separation of a solid dissolved in a solvent from a solvent

Question 18

what is fractional distillation

Answer 18

a technique for separation of a mixture of liquids.
only works when liquids have varied boiling points

Question 19

explain fractional distillation

Answer 19

the fractioning column contains glass beads, that septette the compounds. the column is hot at the bottom and cooler at the top. the liquids rise and condense when they reach their boiling point. the lower boiling point compounds will rise higher and condense.

Question 20

what is filtration

Answer 20

filtration is used to separate an insoluble solid is suspended in liquid

Question 21

explain filtration

Answer 21

the insoluble solid gets caught in the filter paper, because the particles are to big to fit through the paper. the filtration in the substance that comes through.

Question 22

apparatus for filtration

Answer 22

filter paper
funnel

Question 23

apparatus for fractional distillation

Answer 23

similar to the one for simple distillation
additional fractioning column placed on top of a heat source

Question 24

what is chromatography

Answer 24

used to separate a mixture of substances dissolved in a solvent

Question 25

explain chromatography

Answer 25

in paper chromatography, a piece of paper with a spot containing a mixture in a beaker with some solvent. the bottom of the paper has to be in contact with the solvent. the solvent level will start to rise, thus separating the spot into few different ones

Question 26

what is a separating funnel

Answer 26

a separator funnel is an apparatus for separating immisbiscle liquids. two immiscible liquids of different densities will form 2 distinct layers In the separator funnels. we can run off the bottom layer to a separate vessels

Question 27

describe the plumb-pudding model

Answer 27

the atom is a ball of positive charge with negative electrons embedded in it

Question 28

describe the nuclear model

Answer 28

electrons orbit the nucleus at specific distances

Question 29

how did the nuclear model come about

Answer 29

from the alpha scattering experiment

Question 30

later experiments led to the discovery of smaller, positive particles in the nucleus, what are they?

Answer 30

protons

Question 31

what did the work of James Chadwick provide

Answer 31

the existence of neutrons in the nucleus

Question 32

describe the structure of an atom

Answer 32

the atom has a small central nucleus around these are electrons

Question 33

what is the nucleus made of

Answer 33

protons and neutrons

Question 34

relative charge of protons

Answer 34

1

Question 35

relative charge of neutrons

Answer 35

0

Question 36

relative charge of electrons

Answer 36

-1

Question 37

relative mass of protons

Answer 37

1

Question 38

relative mass of neutron

Answer 38

1

Question 39

relative mass of electrons

Answer 39

very very small

Question 40

explain why atoms are electrically neutral

Answer 40

same no. of protons and electrons

Question 41

radius of an atom

Answer 41

0.1nm

Question 42

what is the name given to the no. of protons in the nucleus

Answer 42

atomic no.

Question 43

atoms of the same element have the same no. of which particle in the nucleus

Answer 43

protons

Question 44

majority of mass of an atomis in the where?

Answer 44

the nucleus

Question 45

what is the mass no.

Answer 45

total no. of protons and neutrons

Question 46

how to calculate no. of neutrons using mass no. and atomic no.

Answer 46

subtract the atomic no. from the mass no.

Question 47

what is an isotope

Answer 47

atoms of the same element that have a different no. of neutrons

Question 48

do isotopes of a certain element have the same chemical properties

Answer 48

they have the same chemical properties as they have the same electronic structure

Question 49

what is the relative atomic mass

Answer 49

the average mass value which takes the mass and abundance of isotopes of an element into account

Question 50

what are ions

Answer 50

ions are charged particles,, they are formed when atoms lose electrons or gain electrons

Question 51

boiling or melting point of metals high or low

Answer 51

high

Question 52

boiling or melting points of non-metals low or high

Answer 52

low

Question 53

what do metals conduct

Answer 53

heat and electricity

Question 54

what do non-metals conduct

Answer 54

nothing graphite does however

Question 55

appearance of metals

Answer 55

shiny

Question 56

appearance of non-metals

Answer 56

dull

Question 57

density of metals

Answer 57

high

Question 58

density of non-metals high or low

Answer 58

low

Question 59

what is formed when a metal reacts with a non-metal

Answer 59

an ionic compound

Question 60

what is formed when a non-metal reacts with a non-metal

Answer 60

a molecular compound containing covalently bonded atoms atoms share electrons as opposed to transferring electrons between each other

Question 61

columns of the period table are called

Answer 61

groups

Question 62

rows of period table are called

Answer 62

periods

Question 63

are elements in the same group similar or different

Answer 63

they may have similar chemical properties as they have the same number of outer shell electrons

Question 64

in terms of energy levels, what are the differences between elements of the same period

Answer 64

they have the same number of energy levels

Question 65

group 0 are more commonly known as

Answer 65

noble gasses

Question 66

elements in the same group have the same number of electrons in their outer shell, what does this tell us about their chemical properties

Answer 66

they have similar chemical properties

Question 67

in terms of shells, what is the difference between elements in the same period

Answer 67

same no. of shells

Question 68

what change in shell no. is seen as one moves down a group

Answer 68

no. of shells increase

Question 69

early periodic tables were incomplete and elements were placed in inappropriate groups if what was to be followed

Answer 69

strict order of atomic weights

Question 70

knowledge of what made it possible to explain why the order based on atomic weights was not always correct

Answer 70

isotopes

Question 71

Mendeleev overcame some problems with the table by doing what

Answer 71

leaving gaps

Question 72

Mendeleev changed the order of some elements based on what

Answer 72

atomic weights

Question 73

the majority of elements are

Answer 73

metals

Question 74

elements that react to form positive ions are...

Answer 74

metals

Question 75

elements that do not form positive ions are...

Answer 75

non-metals

Question 76

elements in group 1 are known as

Answer 76

the alkali metals

Question 77

state 4 characteristics of the alkali metals

Answer 77

all have 1 electron in their outer shell low density are stored under oil to prevent reaction with oxygen or water are soft

Question 78

how do group 1 elements react with non-metals

Answer 78

they form ionic compounds which are soluble white solids which form colourless solutions

Question 79

how do group 1 elements react with water

Answer 79

they release hydrogen and form hydroxides which dissolve to form alkaline solutions, react vigorously with water - fizzes and moves around on the surface on the surface of the water

Question 80

how does reactivity change moving down group 1 and why

Answer 80

reactivity increases as the atoms get larger and the distance between the nucleus and the outer electrons increases and thus the attraction from the nucleus decreases, allowing them to more easily lose electrons

Question 81

5 characteristics of group 7

Answer 81

7 electrons in outer shell coloured vapours diatomic molecules form ionic salts with metals form molecular compounds with non-metals

Question 82

state 3 changes that occur in group 7 as you move down the group

Answer 82

high relative molecular mass higher melting and boiling point less reactive - less easily gain electrons

Question 83

compare group 1 metals with transition metals

Answer 83

group one metals and transition metals are heat and electricity conductors.they are shiny when polished and form ionic compounds with non-metals whereas transition metals have higher densities and higher melting points than group 1 metals, they are less reactive and harder than group 1 metals

Question 84

state 3 common characteristics of transition metals

Answer 84

ions with different charges coloured compounds catalytic properties

Question 85

what is a catalyst

Answer 85

a catalyst is a chemical substance that increases the rate of a chemical reaction it is not used up over the course of the reaction

Question 86

describe properties of noble gases

Answer 86

non-metals, gases, low boiling points, unreactive

Question 87

trends in properties of noble gases as they go down the group

Answer 87

boiling point increases as atoms get heavier