Paper 1 - Topics 1-5 (Year 10) Flashcards
What is the first step of writing an ionic equation?
Step 1: Write an equation and balance it.
2Na(s) + 2HCl(aq) -> 2NaCl(aq) + H2(g)
What is the second step of writing an ionic equation?
Step 2: Split the ions. (Only compounds that are aqueous are split into ions.)
2Na(s)+2H+(aq)+2Cl-(aq) → 2Na+(aq)+2Cl-(aq)+H2(g)
What is the third step of writing an ionic equation?
Step 3: Cancel out spectator ions. (Spectator ions are ions that remain the same in their original states before and after a chemical reaction.)
2Na(s)+2H+(aq)+2Cl-(aq) → 2Na+(aq)+2Cl-(aq)+H2(g)
Turns into:
2Na(s) + 2H+(aq) → 2Na+(aq) + H2(g)
What is the last step of writing an ionic equation?
Step 4: Write a balanced ionic equation
2Na(s) + 2H+(aq) → 2Na+(aq) + H2(g)
What is a mixture?
A mixture consists of two or more elements or compounds not chemically combined together. The chemical properties of each substance in the mixture are unchanged.
How can mixtures be separated?
Filtration, crystallisation, simple distillation, fractional distillation, and chromatography.
What were atoms thought of being before electrons were discovered?
Before the discovery of the electron, atoms were thought to be tiny spheres that could not be divided.
What did the plum pudding model suggest?
The plum pudding model suggested that the atom is a ball of positive charge with negative electrons embedded in it.
What did the alpha particle scattering experiment lead to?
The results from the alpha particle scattering experiment led to the conclusion that the mass of an atom was concentrated at the centre (nucleus) and that the nucleus was charged. This nuclear model replaced the plum pudding model.
What was Niels Bohr change about the nuclear model?
He adapted the nuclear model by suggesting that electrons orbit the nucleus at specific distances. The theoretical calculations of Bohr agreed with experimental observations.
What are the three subatomic particles in an atom, and what are their charges and masses?
Proton: Charge: 1 Mass: 1
Neutron: Charge: 0 Mass: 1
Electron: Charge: -1 Mass: Almost 0
What is an atomic number?
The number of protons in an atom of an element is its atomic number. All atoms of a particular element have the same number of protons.
What is an atoms mass number?
The sum of the protons and neutrons in an atom is its mass number.
What are isotopes?
Atoms of the same element can have different numbers of neutrons; these atoms are called isotopes of that element.
How are elements in a periodic table ordered?
They are arranged in order of their atomic numbers.
What is similar about the atoms in the same group of the periodic table?
Elements in the same group in the periodic table have the same number of electrons in their outer shell (outer electrons) and this gives them similar chemical properties.
Before the discovery of subatomic particles, how did scientists order the elements on the periodic table?
Before the discovery of protons, neutrons, and electrons, scientists attempted to classify the elements by arranging them in order of their atomic weights.
Why is the periodic table widely accepted by scientists today?
Elements with properties predicted by Mendeleev were discovered and filled the gaps. These correct predictions allowed scientists to believe Mendeleev’s table.
What are elements that form into positive ions?
Metals.
What are the elements that do not form positive ions?
Non-metals.
In which group are the noble gases?
Group 0 or Group 8.
Why are noble gases unreactive?
They are unreactive and do not easily form molecules because their atoms have stable arrangements of electrons. The noble gases have eight electrons in their outer shell, except for helium, which has only two electrons.
What are the group 1 metals known as?
The elements in Group 1 of the periodic table are known as the alkali metals.
Why do group 1 metals have specific characteristics?
They have characteristic properties because of the single electron in their outer shell.
What is the approximate size of an atom?
About 0.1 nanometers.
How does the number of protons relate to the number of electrons?
The number of electrons and the number of protons are the same.
If an ion has a 2- charge, how is it’s number of electrons different to protons?
It has two more protons than electrons.
What is the definition of an isotope?
Different forms of the same element, which have the SAME number of PROTONS, but a DIFFERENT number of NEUTRONS.
What is the difference between carbon 12 and 13?
Carbon-13 has one more neutron than carbon-12.
What is the formula for relative atomic mass?
sum of (isotope abundance x isotope mass number)
/
sum of abundances of all the isotopes.
How does ionic bonding work?
The metal atom loses electrons to form positive ions and the non-metal atom gains electrons to form negative ions. The opposite charges make them extremely attracted to each other. (the metal gives an electron).
How does covalent bonding work?
Each non-metal atom shares an electron with the other.
What is the formula for Sodium Carbonate?
Na2Co3
What is the formula for Ammonia?
NH3
What is the formula for Calcium chloride?
CaCl2
What is the difference between mixtures and compounds?
There’s no chemical bond between molecules in a mixture, there is in compounds.
Summarise the steps of paper chromatography.
1 - Draw pencil line at bottom of filter paper
2 - Add spot/s of ink on line
3 - Place paper in solvent (usually water)
4 - Solvent goes up paper (osmosis)
5 - Solvent brings dye with it - dye seperates.
What does filtration do?
Filtration seperates insoluble solids from liquids.
What are the two ways to seperate soluble solids from solutions?
Evaporation
Crystallisation
Describe the evaporation method of filtration.
Put solution in evaporating dish and heat, solvent will evaporate leaving crystals.
Describe the crystallisation method of filtration.
Pour solution in evaporating dish and heat a little, solution will concentrate and crystals start to form. Salt should start to form crystals once taken off heat as it becomes insolublein the cold highly concentrated solution. Then filter the crystals out.
What are the 4 processes of seperating rock salt?
1 - Grinding the mixture
2 - Dissolving it
3 - Filtering it
4 - Evaporating it