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Flashcards in Elements of Life Deck (44)
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1

What are isotopes

Atoms of the same element with a different number of neutrons in the nucleus

2

Relative Atomic Mass = ?

(Relative isotopic mass x Relative abundance)/100

3

Speed of light in a vacuum

3x10^8 m/s

4

Wavespeed = ?

Wavelength x Frequency

5

Energy of a photon = ?

Planck constant x Frequency

6

Flame colours of lithium, sodium, potassium, calcium, barium, and copper

Li+ -- Bright red
Na+ -- Yellow
K+ -- Lilac
Ca2+ -- Brick red
Ba2+ -- Apple green
Cu2+ -- Blue green

7

The four main points of Bohr's theory

-Electrons only exist in certain definite energy levels or electron shells
-A photon of light is emitted when electrons change from one energy level to another
-The energy of the photon is equal to the different between the two energy levels
-E = hv

8

How many electrons can an orbital hold and how many orbitals per subshell

Each orbital can hold two electrons
-1 orbital in s sub-shell
-3 orbitals in p sub-shell
-5 orbitals in d sub-shell
-7 orbitals in f sub-shell

9

Which elements have a strange electronic structure?

Copper and chromium. The 4s orbital contains only one electron rather than two

10

Melting and boiling points across period 3

Both melting and boiling points initially increase but fall dramatically after silicon. This means the bonds in phosphorous must be weaker and easier to overcome than those between silicon

11

Covalent bonding

A bond in which electrons are shared between atoms

12

Four points needed to answer a shape and bond angle question

-The shape and the bond angle
-The number of areas of electron density
-Electrons repel to get as far away as possible
-Lone pairs repel more than bond pairs

13

2 x bond pairs

180 degrees, linear

14

3 x bond pairs

120 degrees, trigonal planar

15

4 x bond pairs

109.5 degrees, tetrahedral

16

2 x bond pairs, 1 x lone pair

107 degrees, bent

17

2 x bond pairs, 2 x lone pairs

104.5 degrees, bent

18

3 x bond pairs, 1 x lone pair

107 degrees, trigonal pyramidal

19

5 x bond pairs

120 degrees and 90 degrees, trigonal bipyramidal

20

4 x bond pairs, 2 lone pairs

90 degrees, square planar

21

Moles = ?

Mass (g) / Relative Formula Mass (g/mol)

Concentration (mol/dm3) x Volume (dm3) x 1000

22

Water of crystallisation

The crystals of some ionic lattices include molecules of water. To remove, heat the substance to a constant mass

23

Percentage yield = ?

(Experimental yield / Theoretical yield) x 100

24

Factors which reduce the amount of product produced

-Loss of products from reaction vessels
-Side reactions occurring, producing unwanted by-products
-Impurities in the reactants
-Changes in temperature and pressure
-If the reaction is an equilibrium system

25

Acid + alkali -->
Acid + base -->
Acid + carbonate -->
Acid + metal -->

Salt + water
Salt + water
Salt + water + carbon dioxide
Salt + hydrogen

26

Test for Cu2+

Add sodium hydroxide, if present then blue precipitate will form

27

Test for Fe2+

Add sodium hydroxide, if present then 'dirty' green precipitate will form

28

Test for Fe3+

Add sodium hydroxide, if present then orange/brown precipitate will form

29

Test for Pb2+

Add potassium iodide, if present then bright yellow precipitate will form

30

Test for Cl-

Add silver nitrate, if present then white precipitate will form