Chem Flashcards
What are the horizontal rows on the periodic table called?
periods
What are the vertical columns on the periodic table called?
groups
What is group 1 of the periodic table called?
alkali metals
What is group 2 of the periodic table called?
alkaline earth metals
What is the section in the middle of the periodic table called?
transition metals
What is group 7 in the periodic table called?
the halogens
What is group 0 in the periodic table called?
the noble gases
What side of the periodic table are the non-metals on?
right
What is an atom?
The smallest particle of a chemical element that can exist.
What is an element?
A substance consisting of atoms which all have the same number of protons.
Balance the equation:
Mg+O2→MgO
2Mg+O₂→2MgO
Balance the equation H₂+O₂→H₂O
2H₂+O₂→2H₂O
BaCl₂+LiSO₄→2LiCl+BaSO₄
magnesium+oxygen→
magnesium oxide
Definition of insoluble
A substance that does not dissolve.
Definition of mixture
Two substances that are mixed but not chemically joined.
Definition of distillation
Separates substances with different boiling points.
Soluble definition
A substance that dissolves.
Filtration definition
Separates insoluble substance from soluble substances.
Compound
Atoms of 2 or more elements that are chemically joined.
Crystallisation
Used to obtain a soluble substance from a solution.
Which separation technique separates a liquid from the solid dissolved in it?
simple distillation
Which separation technique separates miscible liquids that dissolve in each other?
fractional distillation
Which separation technique separates soluble substances?
chromatography
Which separation technique separates insoluble solids from liquids?
filtration
Which separation technique separates a solid from the liquid dissolved in it?
crystallisation
Which separation technique works by the solution becoming too concentrated for all the solid to remain dissolved?
crystallisation
Which separation technique works by the liquid evaporating but not the solid?
simple distillation
Which separation technique works by an insoluble substance not passing through filter paper?
filtration
Which separation technique works by one or more insoluble liquid being more attracted to a solid such as paper and therefore not travelling as far as the other?
chromatography
Which separation technique works by liquids with higher boiling points staying in the flask until those with lower boiling points have evaporated?
fractional distillation
What is the use of chromatography?
To identify the dyes used to colour foods.
What is the use of crystallisation?
To obtain pure crystals of compounds used in medicine.
What is the use of simple distillation?
To obtain fresh water from seawater.
What is the use of fractional distillation?
To separate crude oil into different fuels such as petrol and diesel.
What is the use of filtration?
To remove solids before waste water is purified.
When did we discover that everything was made of matter?
1803
Who discovered that everything was made of matter?
John Dalton
Who suggested that elements contain identical atoms?
John Dalton
Who discovered electrons?
JJ Thomson
What do you call tiny particles with a negative charge?
electrons
Who suggested that an atom is a positively charged sphere with negative electrons distributed throughout it?
JJ Thomson
What did Thomson’s model become known as?
the plum pudding model
Who tested the plum pudding model?
Geiger and Marsden
When was the plum pudding model tested?
1909
What did Geiger and Marsden do?
Set up a very thin layer of of gold foil and fired alpha particles.
What happened to the alpha particles in the gold foil?
Most went straight through but some were deflected.
What did Geiger and Marsden prove?
Atoms have a mass in the middle.
Who suggested that an atom is mostly empty space with its positive charge and most of its mass is a tiny central nucleus?
Rutherford
What do electrons orbit?
The nucleus
Which particle was discovered to change the model of an atom?
electron
What type of particle was directed at the gold atoms?
alpha
Which particle has the lowest mass?
electron
Which scientist first suggested that electrons orbit the nucleus at specific distances?
Neils Bohr
Atoms of the same element have the same atomic number because they have the same number of _______.
protons
Atoms have no overall charge because they have the same number of _______ and _________.
protons, electrons
Separating blue food colour from a mixture of food colours is an example of ______________.
chromatography
Separating copper sulphate from copper sulphate solution is an example of ________________.
crystallisation
Scientist now know that atoms are actually made from even smaller particles. What are the three types?
proton
neutron
electron
Protons have what charge?
+1
Neutrons have what charge?
0
Electrons have what charge?
-1
Protons and _______ have the same mass.
neutrons
number of protons + number of neutrons →
mass number
If an atoms has mass number 16 and atomic number 8, how many protons, neutrons and electrons are there?
8,8,8
Whilst atoms of a given element always have the same number of protons, they may have different numbers of neutrons. Atoms which differ in this way are called _________.
isotopes
Which type of substance is hydrogen?
element
Sand can be separated from a mixture of sand and water by __________.
filtration
Suggest what would happen to the temperature of the water as it flows through a condenser?
it gets warmer
How do you obtain sodium chloride solution by crystallisation?
Heat up the solution until the liquid evaporates.
How is the electron arrangement is written?
2,8,8
What is the maximum electrons held in the 1st shell of an atom?
2
What is the maximum electrons held in the 2nd shell of an atom?
8
What is the maximum electrons held in the 3rd shell of an atom?
8
