Question | Answer |
What is the approximate mass of an electron? | 1/2000 |
What charge does a proton carry? | +1 |
What is the particle called that weighs 1 and carries no charge? | A neutron |
What is the mass number of Li? | 7 |
What is the definition of an isotope? | - An element is an atom of the same element with the same number of protons yet different numbers of neutrons |
O(17) has how many more neutrons than O(16)? | 1 |
An atom of O(2+) has how many protons, neutrons and electrons? | P= 8
N= 8
E= 6 |
What is the mass number of potassium (K) | 39 |
Who hypothesized that all matter is composed of atoms? | Dalton (John) |
Who comprised the plum pudding model? | Thomson (Joseph) |
Rutherford was the first person to have evidence that contradicted the plum pudding model. How did he do this? | - He fired alpha particles at an atom
- With the 'gold leaf experiment' |
Bohr introduced a new atom model. Describe one of the changes. | -Atoms flew in paths.
-Energy in orbit is related to size.
-Lowest energy found in smallest orbit. |
Who found a link between atomic number and x-rays? | Mosely |
Chadwick discovered, what? | The neutron. |
What is an ion? | An ion is the lost or gained electrons from an atom. |
What element is used for finding atomic masses? | Carbon-12 |
All the atoms in a sample of a single isotope are identical so have the same mass. What is this definition defining? | Relative Isotopic mass |
Relative atomic mass can be shortened to? | RAM OR Ar |
What is the Mr of(CO2)? | 44 |
What is the difference between Mr and Relative Formula Mass? | RFM is for materials with a giant structure |
What makes a giant structure, giant? | Giant covalent structures contain a lot of non-metal atoms, each joined to adjacent atoms by covalent bonds. |
How would you find the RAM of 2 isotopes? | (abundance or mass/100)x RAM
OR
(ab)+(cd)/100 |
What is the formula triangle for calculating moles with mass and Mr. | Mass
-----------
Moles x mr |
How many moles are there in 13g of sodium? | 0.57 |
(Moles in compound X Moles in each part)/ RAM of element. This works out what? | How much of an element in a substance. |
What is meant by the term Empirical Formula. | The simplest whole number ratio of atoms in a compound. |
Calculate the empirical formula of a substance containing 75% carbon and 25% hydrogen. | CH4 |
The empirical formula of a substance is CH4. The actual weights are 64g, work out actual formula. | C4H16 |
Calculate the mass of 3 moles of SiO2. | 3 x (28.1 + 32)
= 180.3g |
What is Avogadro's number? | 6.022 X 10^-23 |
What is Molar gas volume? | 24dm^3 |
Calculate the moles of 48dm of oxygen. | 2 |
Calculate the volume of 6moles of SO2 | 144dm |
How would you work out concentration? | Number of moles/Volume |
If 25cm of a solution of sodium hydroxide is neutralized by 13.5cm of 0.6mol sulfuric acid. What is the concentration of the alkali? | 1) 2NaOH + H2SO4 ----> 2H2O + Na2SO4
2)N of acid = 8.1 X 10^-3
N of alkali = 0.0162
C of alkali = 0.648 |
Acids are a species that's a ________ donor. | proton |
What is the formula of citric acid? | C6H8O7 |
Bases are normally used for ___________ reactions. | Neutralization |
Alaklis dissolve in water to form _________ ions | OH- |
ACID + BASE = | SALT AND WATER |
How many of Na are needed to make 2.95g of NaCl | 1.15g |
In REDOX an uncombined element has what oxidation number? | 0 |
In REDOX, Oxygen has what oxidation number? | -2 |
NH3 ------> N, Reduced or Oxidized? | Reduced |
Cl2 + _______ ------> 2Cl- | 2e- |
The 'Roman Numerals' indicate what in a redox reaction? | The Oxidation Number, e.g. Iron(III)= +3 |
Deduce the oxidation number of Fluorine in CaF2 | +2 |
Determine empirical formula of a compound with 1.472g of Tungsten and 0.384g o oxygen. | W- 1.472/183.9 = 0.008
O- 0.384/16 = 0.024
= WO3 |
Define the term 'First Ionisation energy' | The amount of energy required to remove one electron from 1 mole of a gaseous atom. |
Define the term 'Relative Atomic Mass' | The weighted mean mass of an atom of an element compared to the weight of 1/12th of carbon 12. |
Li(?)----> Li+(?) + e- | (g) or Gas |
What is the equation for the 2nd ionisation energy of Lithium | Li+ -----> Li2+ + e- |
If there is a massive energy spike in ionisation energies what could it indicate. | A shell jump |
What are the 3 factors that affect first ionisation energy. | Atomic Radius
Shielding
Nuclear charge |
What shape is the S sub-shell? | Spherical |
How many electrons can fit in a 'p' shell? | 6 |
Write the orbital configuration for Boron? | 1s2 2s2 2p1 |
Define an ionic bond | An electrostatic attraction between oppositely charged ions. |
Why do ionic bonds conduct electricity when molten? | Because the ions in the compound are now free to move about and carry charge to other ions. |
Draw an ionic bond for Sodium Oxide | [na]2+ [0(with full shell] -2 |
Define a covalent bond | A bond formed by a shared pair of electrons. |
What is the only element that can contently bond with only 6 electrons? | Boron |
Describe how the strength of metals increase across the groups. | 1<2<3 |
What happens in a 'dative covalent bond' | The lone pair of electrons attract a loose H+ |
What is the shape and bond angle of an covalent bond with 2 bonds? | linear 180' |
What is the shape and bond angle of an covalent bond with 3 bonds? | Trigonal Planar 120' |
What is the shape and bond angle of an covalent bond with 4 bonds? | Tetrahedral 109.5' |
What is the shape and bond angle of an covalent bond with 5 bonds? | Trigonal-bi pyramidal 2X120' 2X90' |
What is the shape and bond angle of an covalent bond with 6 bonds? | Octahedral 90' |
What is the shape and bond angle of an covalent bond with one lone pair of electrons? | pyramidal 107.5' |
What is the shape and bond angle of an covalent bond with 2 lone pairs of electrons? | Non-linear or bent 104.5' |
Define 'electonegativity' | Is a measure of the tendency of an atom to attract a bonding pair of electrons in a covalent bond. |
What is a permanent dipole force? | A weak attractive force between permanent dipoles in neighboring polar molecules. |
How are Van Der Walls' forces created? | Due to the movement of electrons, an instantaneous dipole is created causing it to create dipoles in other molecules. |
Are giant covalent structures soluble? | NO |
What happens when a grp 2 metal reacts with oxygen? | Becomes an oxide. |
What happens when a grp 2 metal oxide reacts with water? | It becomes a hydroxide. |
What happens when a grp 2 metal reacts with water? | A hydroxide and hydrogen are produced. |
What happens when a Grp 2 carbonate thermally decomposes? | The metal oxide and CO2 are produced. |
Which halogen will always be displaced? | Asatine |
What colour is Iodine? | Puple |
What halide will dissolve in both dilute and concentrated silver nitrate? | A Chlorine halide. |
What halide will dissolve in only concentrated silver nitrate? | Bromine halide. |