Ch 3 Atoms and Elements

Question 1

what is an atom

Answer 1

an atom is a particle of matter that cannot be broken down further by chemical means

Question 2

what is an element

Answer 2

an element only contains one type of atom

Question 3

what would you see inside an atom

Answer 3

mostly empty space with a tiny nucleus at the centre and a cloud of electrons orbiting at a high speed at (a) (dif specific) distance(s)

Question 4

what group are the metals on the periodic table

Answer 4

Group I or II

Question 5

what group are the non-metals on the periodic table

Answer 5

Group 0 or IV

Question 6

short form describing an element

Answer 6

proton number at the top, nucleon number at the bottom, element on the side

Question 7

what are isotopes

Answer 7

atoms of the same element with the same proton number but a different neutron number

Question 8

name three isotopes of carbon

Answer 8

carbon-12, carbon-13, carbon-14

Question 9

what is a radioisotope

give 2 examples

Answer 9

radioactive isotope
isotope of an element with an unstable nucleus that will decay and emit radiation

eg. cobalt-60, carbon-14, uranium-235

Question 10

how do you use radioisotopes to check for leaks

Answer 10

Mix radioactive material with the fluid inside the pipe, radiation cannot be detected through the pipe but it can be detected where it leaks out with a Geiger counter

Question 11

name some uses of radioisotopes

Answer 11

Check for leaks
Treat cancer
Kill germans and bacteria

Question 12

why are spices often treated with radiation, name 2 radioisotopes used for this

Answer 12

to kill germs or micro-organisms that cause decay

cobalt-60 and caesium-137

Question 13

why can radiation kill us

Answer 13

it can kill cells, damage organs, cause cancer, radiation sickness

Question 14

why is radiation used for cancer

Answer 14

it kills cancer cells more readily than it kills healthy cells

Question 15

what does the period number tell you

Answer 15

the number of shells there are

Question 16

what does the group number tell you

Answer 16

the number of valency electrons there are

Question 17

isotopes of the same element have the same number of _____ ______
meaning that their _____ are the same

Answer 17

valency electrons

chemical reactions are the same

Question 18

If the outer shell is full ….?

Answer 18

outer shell has a stable arrangement so the atom will be unreactive

Question 19

name the metals and non metals in the first 20 elements

Answer 19

metals: (Lithium) Li , (Beryllium) Be, (Sodium) Na, (Magnesium) Mg, (Aluminium) Al, (Potassium) K, (Calcium) Ca (7) (Li Be Na Mg Al K Ca)
non-metals: H, He, B, C, N, O, F, Ne, P, S, Cl, Ar (12)
metalloids: B, Si

Question 20

define conductor

Answer 20

a substance that allows heat and electricity to pass through it easily

Question 21

define brittle

Answer 21

breaks up easily when struck

Question 22

define ductile

Answer 22

can be easily be drawn out into a wire

Question 23

define sonorous

Answer 23

makes a ringing noise when struck

Question 24

define density

Answer 24

mass per unit of volume

Question 25

define malleable

Answer 25

can be bent/hammered into shape

Question 26

why is aluminium used for outdoor electricity cables

Answer 26

good conductor
light
most abundant metal
quite strong
light
forms protective layer so won't rust away

Question 27

three main general properties that distinguish metals from non-metal

Answer 27

metals form positive ions when they react (eg. Na+) with the exception for a non-metal being H+

conduct electricity

hard and strong

high melting points

Question 28

physical properties of non-metals

Answer 28

doesnt conduct electricity or heat
lower melting and boiling points- many are gases at rpo temperature
brittle
not malleable or ductile
dull in solid state
solid non-metals have low density

Question 29

chemical properties of non-metals

Answer 29

often form negative ions when they react eg O 2-

React with oxygen to form ACIDIC OXIDES
aqueous solutions will turn litmus RED

Question 30

chemical properties of metals

Answer 30

form positive ions when they react (eg. Na+)

react with oxygen to form oxides that are BASES
oxides can NEUTRALISE ACIDS

Question 31

name some metals that have a low density

Answer 31

aluminium
sodium
lithium
potassium

Question 32

explain how the chemical properties of metals and non-metals can be used to tell them apart

Answer 32

metals from BASIC OXIDES

non-metals form ACIDIC OXIDES