atomic structure and the periodic table

Question 1

what is an elemnt

Answer 1

an elemnt is a substance made up of only one type of atom

Question 2

what is a compound

Answer 2

two or more elements combined chemically

Question 3

do compounds have the same properties as their constituent elements

Answer 3

no they have different properties

Question 4

what is a mixture

Answer 4

a mixture consists of two or more elements not chemically combined together. it does have the same properties as its constituent materials

Question 5

what are the methods mixtures can be seperated

Answer 5

filtration, crystallisation, simple distillation, fractional distillation, and chromatography

Question 6

describe and explain simple distillation

Answer 6

• used to separate liquid from a solid.
• the liquid boils of and condenses in the condenser.
• the thermometer will read the boiling point of the pure liquid
• you keep the liquid

Question 7

what is a seperating funnel

Answer 7

• appratus for separating imiscble liquids.
• two immiscible liquids of two different densities will form two distinct layers in the separatory funnel.
• we can run off the bottom layer into a seperate conainer.

Question 8

describe the plum pudding model

Answer 8

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

Question 9

describe the nuclear model

Answer 9

the nuclear model suggests that electrons orbit at specific distances on shells , it came about from the alpha scattering experiment.

Question 10

what did james chadwick provide energy for

Answer 10

the existance of neutrons in the nucleus

Question 11

describe the structure of an atom

Answer 11

the atom has a small centural nucleus made up of protons and neutrons, which electrons orbit on shells

Question 12

releative charges of protons neutrons and electrons

Answer 12

proton - 1
neutron - 0
electron - -1

Question 13

releative masses of protons neutrons and electrons

Answer 13

proton -1
neutron - 1
electron - very small

Question 14

why are atoms electrically neutral

Answer 14

they have the same number of electrons and protons

Question 15

what is atomic number

Answer 15

the number of protons in the nucleus

Question 16

where is the majority of the mass in the atom

Answer 16

the nucleus

Question 17

what is the mass number

Answer 17

the total number of protons and nuetrons

Question 18

what is an isotope

Answer 18

atoms of the same element with the same number of protons but a different number of neutrons. they have the same chemical properties as the have the same chemical structure

Question 19

what is relative atomic mass

Answer 19

the avarage mass value which takes into account the mass and abundance of isotopes o an element on a scale where the mass of 12C is 12

Question 20

what are ions

Answer 20

• ions are charged particles
• they are formed when atoms lose elecrtons (postive ions) or gain electrons (negative electrons)

Question 21

compare the properties of metals and non - metals

Answer 21

Question 22

what is fromed when a metal rects with a non-metal

Answer 22

an ionic compound (made up of posotive and negative ions)

Question 23

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

Answer 23

a molecular compund containing covanlently bonded atoms. atoms share electrons as opposed to transferring electrons between each other.

Question 24

what is a soulut what is a solvent

Answer 24

-solute = a substance that is dissolved in a solvent together they from a solution

Question 25

what does miscible and immiscible mean

Answer 25

miscible refers to substances that mix together e.g water and alcohol.
immiscible means they do not mix e.g water and oil

Question 26

are elemnts in the same group similar

Answer 26

yes they may have similar chemical properties as they have the same number of atoms on the outer shell

Question 27

what are group 0 known as

Answer 27

noble gases

Question 28

what happens in the shell number when you move down the group

Answer 28

the number of shells increases

Question 29

what made is possible to explain why the order absed on atomic wheights is not always correct

Answer 29

isotopes