Unit 1: Atomic Structure & Periodicity Test

Question 1

matter

Answer 1

anything that has mass and takes up space

Question 2

element

Answer 2

simplest form of matter. Composed of only one type of atom. Elements cannot be broken down into simpler substances

Question 3

pure substance

Answer 3

made up of one type of particle, thus they include elements. Pure substances have specific and consistent properties

Question 4

compounds

Answer 4

occur when 2 or more elements chemically bond together

Question 5

mixture

Answer 5

when 2 or more pure substances are physically mixed together, thus no chemical reaction/change has taken place and no new substances have been formed

Question 6

heterogenous mixture

Answer 6

when 2 or more substances are mixed and the composition is not uniform throughout the mixture. You can visibly see that there are different substances mixed together

Question 7

homogenous mixture

Answer 7

when 2 or more substances mix with a uniform composition at the particle level. A homogenous mixture appears as one substance

Question 8

atom

Answer 8

A single particle of an element

Question 9

molecules

Answer 9

particles composed of two or more atoms chemically bonded

Question 10

ions

Answer 10

particles with an overall charge due to an imbalance of protons and electrons. Negative ions or anions have more electrons than protons. Positive ions or cations have less electrons than protons

Question 11

isotopes

Answer 11

atoms with the same number of protons (atomic no.) but a different number of neutrons (mass no.)

Question 12

frequency

Answer 12

the number of waves that pass in one second

Question 13

wavelength

Answer 13

distance between two peaks

Question 14

relationship between properties of a wave

Answer 14

inverse relationship where a shorter wavelength produce higher frequency, and a longer wavelength produce a lower frequency

Question 15

rank types of electromagnetic radiation in terms of increasing wavelength and decreasing energy (frequency)

Answer 15

(infrared) ROY G BIV (ultra violet)

Question 16

spectrum

Answer 16

a band of colours, as seen in a rainbow, produced by separation of the components of light by their different degrees of refraction according to wavelength.

Question 17

continuous spectrum

Answer 17

a spectrum that consists of light at all wavelengths without interruption. Hot dense objects produce a continuous spectra

Question 18

emission spectrum

Answer 18

a spectrum that only emits light at specific wavelengths, producing only a fe lines of colour. hot gases produce emission spectra

Question 19

absorption spectrum

Answer 19

a spectrum that looks like a rainbow with black lines removed at specific wavelengths. they are created when the light of an object that produces a continuous spectrum passes through a cloud of cool gas

Question 20

spectrograph

Answer 20

instrument that uses a prism or diffraction grating to split light into its component wavelengths.

Question 21

ionisation energy

Answer 21

energy to remove (1 mol) an electron from (1 mol of) a GASEOUS atom
equation: H(g) –> H+ (g) + e-

Question 22

electron affinity

Answer 22

energy change when a gaseous atom gains an electron
equation: H(g) + e- –> H(g)-

Question 23

first ionisation energy

Answer 23

the energy required to remove 1 mole of electrons from 1 mole of gaseous atoms

Question 24

successive ionisation energies

Answer 24

the energy required (per mole) to remove more than one electron from an atom. e.g. oxygen can have up to 8 successive ionisation energies, removing all 8 of its electrons

Question 25

limit of convergence

Answer 25

theoretical value for ionisation energy; where the energy levels converge (on an energy level diagram) represents ionisation energy

Question 26

effective nuclear charge (Z/Zeff)

Answer 26

the net electrostatic attraction experienced by valence electrons for the nucleus of an atom. (the overall pull that the nucleus of an atom has on its outermost (valence) electrons)

Question 27

effects of atomic structure on Zeff

Answer 27

1) number of principle energy levels
* the higher the energy level the farther away the electron is from the nucleus + the more inner shell electrons which result in a greater shielding effect of the nucleus’ positive charge
* more energy levels = lower Zeff
2) number of protons
* more protons = more positive charge in the nucleus, causing electrons to experience more attraction
* when the atoms’ shielding effect is equal (in the same period (row)): more protons = higher Zeff
3) number of electrons
* when atoms have the same number of energy levels and protons, the only thing left to compare is their electrons. With this, more electrons = lower Zeff
* more electrons = more electron repulsion, resulting in a reduction of the attraction felt by each valence electron

Question 28

atomic radius

Answer 28

the size of an atom of a given element (half the distance between two neighbouring nuclei) - usually listed in picometers (pm)

Question 29

ionic radius

Answer 29

the size of an ion of a given element (based on the distance between two neighbouring nuclei) - usually listed in picometers (pm)

Question 30

electronegativity

Answer 30

the relative ability of an atom to attract an electron pair when bonding

Question 31

types of electron orbitals and their shapes

Answer 31

1) s orbitals: sphere. comes in 1s, 2s, 3s
2) p orbitals: propeller. comes in 2px, 2py, 2pz
3) d orbitals: clover. comes in dyz, dxz, dxy, dy^2x^2, dz^2 (weird shape)

Question 32

oxidation state (or oxidation number)

Answer 32

a number assigned to an atom to show the number of electrons transferred in forming a bond. The term s used interchangeably with “charge.” e.g.
oxidation state: +1, +2, -2
ion symbol with charge: Na1+, Ca2+, O2-

Question 33

absorption on an energy level diagram

Answer 33

arrow between energy levels pointing UP

Question 34

emission on an energy level diagram

Answer 34

arrow between energy levels pointing DOWN

Question 35

UV region on an energy level diagram

Answer 35

transitions down to n=1

Question 36

Visible region on an energy level diagram

Answer 36

transitions down to n=2

Question 37

infrared region on an energy level diagram

Answer 37

transitions down to n=3

Question 38

ionisation energy on an energy level diagram

Answer 38

n=1 to n= infinity

Question 39

relative atomic mass

Answer 39

weighted average of the masses of all the isotopes of an element based on their abundance. All other atomic masses are relative to the mass of carbon-12. 1 atom of carbon-12 weighs exactly 12 amu, hence being the standard for atomic mass.