Atomic structure

Question 1

define an element

Answer 1

a pure substance consisting of 1 type of atom that cannot be split or broken down into simpler substances by any chemical means

Question 2

define an atom

Answer 2

the smallest particle of element that can take place in a chemical reaction

Question 3

what is a postulate

Answer 3

a postulate is a statement that is accepted as true without proof

Question 4

define atomic number

Answer 4

the number of protons in the nucleus of an atom of an element

Question 5

what is thermal decomposition

Answer 5

the decomposing of a substance by heat

Question 6

what is an anode and a cathode

Answer 6

anode- positive electrode

cathode- negative electrode

Question 7

what does AMU stand for

Answer 7

atomic mass unit

Question 8

what device is used to measure/compare the mass of different atoms

Answer 8

a mass spectrometer

Question 9

define isotope

Answer 9

atoms of the same element with the same atomic number but different mass numbers

Question 10

what is electron configuration

Answer 10

the way in which electrons are arranged around the nucleus

Question 11

what is the ground state

Answer 11

the lowest energy level [most stable]

Question 12

what is the excited state of an electron

Answer 12

when an electron absorbs a certain amount of energy and can move to a higher energy level

Question 13

define orbital

Answer 13

region of space around the nucleus where there is a 90% chance/probability of finding an electron

Question 14

state Pauli’s exclusion principle

Answer 14

an orbital can have a maximum of 2 paired electrons, which spin in opposite directions

Question 15

state Hund’s rule

Answer 15

a single electron occupies each orbital before electrons pair

Question 16

what are nucleons

Answer 16

protons and neutrons collectively

Question 17

what are valence electrons

Answer 17

the number of electrons that are found in the outer most energy level

Question 18

what are valency electrons

Answer 18

the number of unpaired electrons (bonding electrons)

Question 19

what are inert gases

Answer 19

elements that are unreactive and have chemical stability (noble gases)

Question 20

what is the charge of a proton and neutron

Answer 20

proton- +1

neutron-0

Question 21

where is the electron found

Answer 21

in fixed orbits

Question 22

what is the lowest energy level called

Answer 22

the ground state

Question 23

state the 3 of Daltons postulates

Answer 23

all matter is made up of indivisible indestructible particles called atoms
atoms of a given element are identical
an atom is the smallest particle of an element which can take place in a chemical reaction

Question 24

the mass of each atom is relative to which element/isotope

Answer 24

carbon-12

Question 25

what is the name given to electrons found in the inner most shell

Answer 25

core electrons

Question 26

what happens when a electron falls back to a lower energy state

Answer 26

the electron releases the same amount of energy it absorbed in the form of light

Question 27

what do you call it when a electron releases energy in the form of light

Answer 27

we say the energy has being quantized

Question 28

what shape does the 1S orbital have

Answer 28

a spherical shape

Question 29

what shape do P orbitals have

Answer 29

a hourglass shape (two teared shaped halves)

Question 30

who created the plum pudding model and discovered electrons

Answer 30

JJ Thomson

Question 31

who was the first person to discover the atom

Answer 31

Democritus

Question 32

who discovered the nucleus

Answer 32

Ernest Rutherford

Question 33

who discovered orbitals

Answer 33

Schrodinger

Question 34

who discovered the neutron

Answer 34

James Chadwick