Atomic Structure

Question 1

element

Answer 1

a pure substance made up of one type of atom

Question 2

molecules

Answer 2

a group of different atoms chemically bonded together

Question 3

chemical reaction

Answer 3

rearrangement of atoms

Question 4

how is periodic table ordered?

Answer 4

from left to right in order of increasing atomic mass

Question 5

who proposed the Plum Pudding model?

Answer 5

Thompson

Question 6

what did Thompson experiment with?

Answer 6

cathode-ray tubes

Question 7

what did Thompson conclude?

Answer 7

electrons travel in straight lines from cathode

Question 8

what did Rutherfords planetary model propose?

Answer 8

nucleus contained positive protons and no charge neutrons
nucleus has majority of the mass
atom mostly empty space
electrons are negatively charged and they orbit the nucleus in electron shells

Question 9

how is mass of nucleus measured?

Answer 9

in atomic mass units (AMUs)

Question 10

what does an alpha particle contain?

Answer 10

2 protons
2 neutrons

Question 11

Atomic Number (Z)

Answer 11

number of protons
atomic number is specific to each element

Question 12

What letter correlates with atomic number

Answer 12

Z

Question 13

atomic mass (A)

Answer 13

total number of protons and neutrons in the nucleus

Question 14

what letter correlates with atomic mass?

Answer 14

A

Question 15

what is an isotope?

Answer 15

atoms of the same element with different number of neutrons
same number of protons

Question 16

what do different electron shells represent?

Answer 16

different levels of potential energy

Question 17

what do electron shells allow?

Answer 17

allow electrons to exist without making any collisions

Question 18

what are the shell letters and what is the max number of electrons in the shell?

Answer 18

K - 2
L - 8
M - 18
N - 32

Question 19

what happens when an atom gains electrons?

Answer 19

becomes negatively charged
negative ion
anion

Question 20

what happens when an atom loses electrons?

Answer 20

becomes positively charged
positive ion
cation

Question 21

what is binding energy?

Answer 21

amount of energy required to remove the electron from its atom

Question 22

what does binding energy depend on?

Answer 22

number of protons in nucleus of atom
proximity of electron to nucleus

Question 23

what is binding energy measured in?

Answer 23

electron volts (eV)

Question 24

what is an electron volt (eV)?

Answer 24

amount of energy an electron acquires from a potential difference of 1V

Question 25

what can ionise atoms?

Answer 25

x-rays electrons

Question 26

what can x-ray and electrons do?

Answer 26

can remove shell-bound electrons BUT only if they have sufficient energy

Question 27

how does ionisation occur?

Answer 27

energy transfers to the electron and overcomes the binding energy of the bound electron - if its not enough energy the electron cannot escape

Question 28

what happens if the energy isn’t sufficient to ionise the atom?

Answer 28

the electron might only climb to a shell further from the nucleus - this can produce a lot of heat which is an issue for x-ray tubes