Chapter 1 Definitions

Question 1

alpha particles

Answer 1

a particle containing two protons and two neutrons, aka helium nucleus

Question 2

element

Answer 2

a pure substance made up of atom of the same atomic number

Question 3

periodic tabe

Answer 3

a chart of the elements, arranged in increasing atomic number; it is organised into groups and periods to show trends in the elements

Question 4

synthetic element

Answer 4

element that does on exist in nature, but has been made in a laboratory

Question 5

atomic number

Answer 5

the number of protons in an atom

Question 6

mass number

Answer 6

the total number of protons and neutrons in an atom

Question 7

electrostatic attraction

Answer 7

a force that pulls the particles together when they have an opposite charge

Question 8

electrostatic repulsion

Answer 8

a force that pushes particles apart when they have an identical change

Question 9

strong nuclear force

Answer 9

an attractive force that exists between particles in the nucleus; it is a short-range force acting only on adjacent particles

Question 10

isotopes

Answer 10

different forms of an element with the same number of protons but different number of neutrons

Question 11

chemical properties

Answer 11

a property of a substance relating to its ability to change to new substances during chemical reactions

Question 12

relative atomic mass

Answer 12

the mean mass of an element that takes into account the isotope masses and the relative abundance on Earth; it is measured against carbon-12

Question 13

physical properties

Answer 13

an observable feature of a substance that can be measured without changing the identity of the substance, such as colour, density, hardness

Question 14

radioactive decay

Answer 14

the spontaneous disintegration of an atom due to instability in the nucleus, during which particles or electromagnetic radiation are released

Question 15

periods

Answer 15

a horizontal row of elements in the periodic table that gives information on the number of energy level s occupied by electrons

Question 16

groups

Answer 16

a vertical column in the periodic table that gives information on number of valence shell electrons and trends between atoms

Question 17

alkali metals

Answer 17

the common name for elements found in group 1 of the periodic table

Question 18

transition elements

Answer 18

elements found between groups 2 and 13 in the periodic table, also known as the d-block elements

Question 19

reactivity

Answer 19

the likelihood of an element or substance undergoing a chemical reaction

Question 20

metalloid

Answer 20

an element that has properties of both metals and non metals

Question 21

nanotechnology

Answer 21

a branch of science dealing with particles in the range of 1-100 nanometres

Question 22

allotropes

Answer 22

a different physical form of the same element

Question 23

energy levels (energy shells)

Answer 23

a region of the atom in which electrons of the same energy can be found

Question 24

electron configuration

Answer 24

the arrangement of electrons around an atom in their energy levels

Question 25

subshells

Answer 25

a part of an energy level that contains orbitals of the same energy

Question 26

atomic orbitals

Answer 26

the region of space around an atom that has a specific shape and may contain a maximum of two electrons

Question 27

lanthanoids

Answer 27

period of the periodic table that, along with the actinides, make up the f block

Question 28

actinoids

Answer 28

the period on the periodic table that, along with lanthanides, make up the f block

Question 29

electron shell diagram

Answer 29

a visual representation of electrons in their energy levels around the nucleus

Question 30

electron charge cloud diagrams

Answer 30

a visual representation of the region of space around a nucleus where an electron might be found

Question 31

atomic orbital diagram

Answer 31

a diagram showing the space electrons occupy in one of four orbitals -s, p, d, f

Question 32

valence (outer) shell

Answer 32

the outermost shell of an atom that contains electrons

Question 33

atomic radius

Answer 33

the distance from the nucleus to the boundary of the cloud of electrons surrounding it

Question 34

ionisation energy

Answer 34

the amount of energy needed to remove an electron from a neutral atom when it is a gas

Question 35

electronegativity

Answer 35

the relative ability of an atom to attract electrons

Question 36

electron affinity

Answer 36

the ability of an atom in the gaseous state to accept an electron and form a negative ion

Question 37

ground state

Answer 37

when all the electrons of an atom are at their lowest possible energy levels

Question 38

excited state

Answer 38

when an electron is in a higher energy level than the ground state due to absorption energy

Question 39

wavelength

Answer 39

a property of light related to the length of the wave, which can give properties of light such as colour

Question 40

spectroscopy

Answer 40

the branch in chemistry involving absorption and emission of light from substances

Question 41

spectroscope

Answer 41

a device used to separate light into ins component wavelengths

Question 42

line emission spectrum

Answer 42

a pattern of lines showing the component wavelengths in light

Question 43

vaporised

Answer 43

when a substance is heated so that it turns into its atomic form

Question 44

atomic absorption spectroscopy

Answer 44

an analytical technique for determining the unknown

Question 45

quantitative analysis

Answer 45

analysis that measures values such as amount, concentration or volume rather than just identifying the substance

Question 46

monochromator

Answer 46

a device used in atomic absorbance spectroscopy to select light of a single wavelength

Question 47

detector

Answer 47

a device used to measure light or particles, found in both atomic absorption spectroscopy and mass spectrometry processes

Question 48

absorbance

Answer 48

a measurement taken by a machine that compares the light passing into a substance with that existing and gives a value

Question 49

calibration curve

Answer 49

a graph constructed during atomic absorption spectroscopy that plots known concentrations against the absorbance values, used to determine the concentration of an unknown substance

Question 50

mass spectrometry

Answer 50

an analytical method that uses the different masses of particles to measure their relative abundance in a sample

Question 51

isotopic composition

Answer 51

the number and amount of isotopes within a sample of an element

Question 52

ultra violet light

Answer 52

invisible, high energy, high frequency light