Atomic theory

Question 1

what did the greeks say about the atom

Answer 1

matter its made up of tiny indivisible particles
- had no proof
- greek for indivisible in atomos

Question 2

Daltons atomic theory

Answer 2

All matter is made from small particles called atoms
atoms are indivisible -> cannot be broken into simpler substances

Question 3

what is atomic theory

Answer 3

the idea that matter is composed of small particles
‘particular nature of matter’

Question 4

daltons experiement to prove the particular nature of matter

Answer 4

glass tube with a stopper on either end
cotton wool soaked in concentrated ammonia solution at one end
cotton wool soaked in concentrated hydrogen chloride solution at the other end
white cloud forms in the middle –> ammonium chloride

Question 5

results of atomic theory experiment

Answer 5

particles of the ammonia gas move to meet with the particles of hydrogen chloride
A white cloudy substance is formed = ammonium chloride

Question 6

electrons
who named
who discovered

Answer 6

George stoney named
William Crookes assisted in discovery
JJ thompson discovered

Question 7

facts about electrons

Answer 7

mass = 0
charge = -1
have enough energy to move a paddle wheel

Question 8

CNAP

Answer 8

Cathode negative
Anode positive

Question 9

what were the observations of Crookes vacuum tube

Answer 9

rays coming from the cathode struck the anode and cast a shadow at the end of the tube

Question 10

what were the observations of Crookes paddle wheel

Answer 10

the paddle wheel roared down the rail from the cathode to the anode

Question 11

what could be concluded from Crookes experiments

Answer 11

cathode rays are invisible
they possess enough energy to move and rotate a paddle wheel

Question 12

George Stoney

Answer 12

named negatively charged particles before their discovery

Question 13

who named negatively charged particles

Answer 13

George stoney

Question 14

who discovered electrons

Answer 14

JJ Thompson

Question 15

What is Thompsons plum pudding model

Answer 15

says that an atom is a sphere of positive charges with negative charges embedded throughout

Question 16

what are cathode rays

Answer 16

invisable rays of negatively charged particles called electrons

Question 17

what is JJ Thompson accredited with other than the discovery of the electron

Answer 17

calculated the e over m ratio
charge over mass

Question 17

what is Robert milkman accredited with

Answer 17

calculating the size of the charge of the electron which could be substituted into Thompsons e over m ratio
hence discovered the mass

Question 18

what experiment did robbery milkman do

Answer 18

oil drop

Question 19

what did James Chadwick do

Answer 19

bombarbed beryllium with alpha particles
discovered neutrons

Question 20

why is the discovery of neutrons the most important

Answer 20

neutrons can be used to split atoms of uranium to release nuclear energy used for atonic bombs

Question 21

charge and mass of neutrons

Answer 21

no charge
mass of 1

Question 22

charge and mass of protons

Answer 22

positively charged
mass of 1

Question 23

who discovered the nucleus

Answer 23

Ernest rutherford

Question 24

who discovered the proton

Answer 24

Ernest Rutherford

Question 25

what did Ernest Rutherford foo

Answer 25

discover protons and the nucleus

Question 26

what is matter

Answer 26

anything that takes up space

Question 27

what are atoms

Answer 27

smallest particle of matter that can exist by itself (neutral)

Question 28

what are molecules

Answer 28

groups of atoms chemically joined

Question 29

what are ions

Answer 29

atoms or groups of atoms with a charge

Question 30

what are alpha particles

Answer 30

a particle that consists of 2 neutrons and 2 protons

Question 31

where is americium 241 used

Answer 31

smoke alarms

Question 32

what are properties of alpha particles

Answer 32

not very penetrating- can be stopped by a few cm3 of air or sheet of paper positively charged - consists of 2 protons and 2 neutrons damages cells - cause cancer mass 4