Chapter 2 - Elements and the Periodic Table

Question 1

alkali metals

Answer 1

a group 1 metal; Li, Na, K, Rb, Cs, Fr

Question 2

atom

Answer 2

basic building block of matter, which is made up of the subatomic particles protons, neutrons and electrons

Question 3

atomic number

Answer 3

the number of protons in the nucleus of the atom; equal to the number of electrons

Question 4

atomic radius

Answer 4

a measurement used for the size of atoms; the distance from the nucleus to outermost electrons

Question 5

atomic theory of matter

Answer 5

all matter is made up of atoms; atoms are indivisible, atoms of the same element are identical and compounds are made up of different types of atoms in fixed ratios

Question 6

block (periodic table)

Answer 6

one of four main parts of the periodic table where elements have the same highest energy subshell filled

Question 7

Bohr model

Answer 7

a theory of the atom proposed by Niels Bohr which states that electrons in an atom occupy fixed, circular orbits that correspond to specific energy levels

Question 8

chemical symbol

Answer 8

a symbolic representation of an element where the first letter is capitalised and the second letter is lowercase

Question 9

compound

Answer 9

a pure substance made up of different types of atoms combined in a fixed ratio

Question 10

condensed electronic configuration

Answer 10

a shortened way of writing electronic configuration by using the noble gas before the element

Question 11

conflict element

Answer 11

elements mined in areas of war and conflict, which makes their use unsustainable

Question 12

critical element

Answer 12

element heavily relied on by industry and society, which faces some form of supply uncertainty

Question 13

effective nuclear charge

Answer 13

the net positive charge experienced by an electron in an outer shell of an atom; indicates the attractive force felt by the valence electrons towards the nucleus

Question 14

electron

Answer 14

a negatively charged subatomic particle that occupies the region around the nucleus of the atom

Question 15

electronic configuration

Answer 15

(in the shell model of an atom) a means of representing the number of electrons in each shell

Question 16

electron shell

Answer 16

(in the shell model of an atom) the fixed energy level that corresponds to a circular orbit of the electrons
(in the Schrodinger model) a shell contains subshells and orbitals of equal or similar energy

Question 17

electronegativity

Answer 17

the ability of an atom to attract electrons in a covalent bond towards itself

Question 18

electrostatic attraction

Answer 18

the force of attraction between a positively charged particle and a negatively charged particle

Question 19

element

Answer 19

a substance made up of atoms with the same atomic number

Question 20

emission spectrum

Answer 20

a spectrum produced when an element is excited by heat or radiation; appears as distinct lines characteristic of the element

Question 21

endangered element

Answer 21

element at risk of depletion on Earth, as natural deposits are used up

Question 22

energy level

Answer 22

one of the different shells of an atom in which electrons can be found

Question 23

excited state

Answer 23

describes an atom in which electrons occupy higher energy levels than the lowest possible energy levels

Question 24

first ionisation energy

Answer 24

the energy required to remove one electron from an atom of an element in the gas phase

Question 25

flame test

Answer 25

a test for the presence of certain metal ions or metals; when burnt in a flame, certain metals and metal ions produce a colour

Question 26

ground state

Answer 26

a term used to describe an atom in which the electrons occupy the lowest possible energy levels

Question 27

group (periodic table)

Answer 27

a vertical column of elements in the periodic table

Question 28

halogen

Answer 28

a group 17 element; F, C, BR, I, At

Question 29

ion

Answer 29

a positively or negatively charged atom or group of electrons

Question 30

isotope

Answer 30

each of two or more forms of the same element that contain equal numbers of protons but different numbers of neutrons in their nuclei

Question 31

main group element

Answer 31

an element in groups 1,2 or 13-18 in the periodic table

Question 32

mass number

Answer 32

the number of protons and neutrons in the nucleus of an atom

Question 33

matter

Answer 33

anything that has mass and occupies space

Question 34

metalloid

Answer 34

an element that displays both metallic and non-metallic properties; germanium, silicon, arsenic, tellurium

Question 35

model

Answer 35

a description that scientists use to represent the important features of what they are trying to describe

Question 36

neutron

Answer 36

an uncharged subatomic particle found in the nucleus of an atom

Question 37

noble gas

Answer 37

an unreactive gaseous element in group 18 of the periodic table; with the exception of helium, noble gases have 8 electrons in their outer shells

Question 38

nucleon

Answer 38

a particle that makes up the nucleus of an atom; protons and neutrons

Question 39

nucleus

Answer 39

the positively charged core at the centre of an atom, consisting of protons and neutrons

Question 40

nuclide notation

Answer 40

a way of representing an atom using the element symbol, atomic number (Z) and mass number (A)

Question 41

orbital

Answer 41

a component of a subshell, a region of space in which electrons move and each holds two electrons (Schrodinger model)

Question 42

period

Answer 42

a horizontal row of elements in the periodic table

Question 43

periodic law

Answer 43

the way properties of elements vary periodically with their atomic number

Question 44

periodic table

Answer 44

a table that organises the elements by grouping them according to their electron configurations

Question 45

periodicity

Answer 45

the periodic pattern of properties of the elements

Question 46

proton

Answer 46

a positively charged, subatomic particle bound to neutrons in the nucleus of an atom

Question 47

quantised

Answer 47

in specific quantities or chunks

Question 48

quantum mechanics

Answer 48

a branch of science that describes the behaviour of extremely small particles such as electrons

Question 49

radioactive

Answer 49

spontaneously undergoing nuclear decay to produce radiation such as beta particles, alpha particles and gamma rays

Question 50

Schrodinger model

Answer 50

a model for the behaviour of electrons in atoms that describes electrons as having wave-like properties

Question 51

subatomic particle

Answer 51

a particle that makes up an atom - protons, neutrons and electrons

Question 52

subshell

Answer 52

a component of a shell in the Schrodinger model, made up of orbitals; each subshell can be regarded as an energy level that electrons can occupy

Question 53

transition metal

Answer 53

an element in groups 3-12 of the periodic table

Question 54

valence electrons

Answer 54

an electron found in the valence shell; an outermost electron in an atom or ion

Question 55

valence shell

Answer 55

the highest energy shell (outer shell) of an atom that contains electrons