Chapter 1- Atomic Structure Flashcards
What is a compound?
They are made up of different types of elements bonded together.
What are all substances made of?
Atoms
How many different types of atoms do elements contain?
One
How many types of atoms do compounds contain?
One or more
Describe an atom
It has a tiny nucleus at its centre, surrounded by electrons
Describe the periodic table
The periodic table lists all the chemical elements, with eight main groups containing elements with similar chemical properties
What happens to atoms in chemical reactions? (Does anything happen at all? Do they get destroyed, created or does nothing happen at all?)
Nothing happens to atoms in chemical reactions, the mass of the reactants is the same as the mass of products
How many of each atom are on either side of a chemical equation?
The sides are always equal - chemical equations are always balanced
What does (s) (l) (g) and (aq) mean in chemical equations?
(s) = solid
(l) = liquid
(g) = gas
(aq) = aqueous
Define a mixture
It is made up of two or more substances that are not chemically combined together.
What are the 3 ways of separating mixtures?
Filtration
Crystallisation
Distillation
Describe fractional distillations
An effective way of separating miscible liquids , using a fractionating column. The separation is possible because of the different boiling points of the liquids in the mixture.
Describe paper chromatography
It separates mixtures of substances dissolved in a solvent as they move up a piece of chromatography paper. The different substances are separated because of their different solubilities in the solvent used.
What is a miscible liquid?
Two liquids that have dissolved in each other, mixing completely
What is a immiscible liquid?
Two liquids like oil and water that, once settled, will separate into layers
When using fractional distillation when is it easy to separate miscible liquids?
When the boiling point of the two liquids is far apart such as water and ethanol
What are atoms made of?
Protons
Neutrons
Electrons
What charge do protons, electrons and neutrons have?
Protons = +1 charge Electrons = -1 charge Neutrons = neutral charge
What is the relative mass of a proton and a neutron.
They are both 1
Do atoms contain an equal number of protons and electrons?
Yes they contain no overall charge
What is the atomic number?
It is the number of protons which is equal to the number of electrons
What is the mass number?
The number of protons and neutrons combined
Do atoms of the Same element have the same number of protons and electrons in their atoms.
Yes
What are negative ions?
They are atoms that gain electrons
What are positive ions?
If atoms lose electrons they form positive ions
Where on a elements are the mass number and atomic number ( top or bottom)?
Atomic number is at the bottom
Atomic mass is at the top
What are isotopes?
Isotopes are different forms of the same element, which have the SAME number of PROTONS, but a different number of NEUTRONS
How are electrons arranged?
They are arranged in energy levels or shells
How many electrons can each shell hold?
The first can hold 2 electrons the rest can hold 8
What does the amount of electrons in the outer shell show?
The way in which the element reacts, a outer shell with a low amount of electrons will be more reactive than a full outer shell
What is the difference between a compound and a mixture?
A mixture is not chemically bonded a compound is
What is the plum pudding theory?
A theory by J J Thompson he said that it was a ball of positive energy with negatively charged electrons lodged in it.
What is the alpha particle test?
A test where they shot positively charged alpha particles at a thin gold sheet. According to the plum pudding theory they would go straight through however some deflected backwards off the nucleus because of its positive charged and the model we use today was thought up
Describe the process of paper chromatography.
First a pencil line is drawn at the bottom.
Different coloured inks are dotted along the bottom.
Next the paper is dipped into the solvent.
The ink will move up the paper with the solvent.
When it is near the top take it out the beaker and leave it to dry.
The end result is a chromatograph
Which method of separation is used to separate an insoluble solid from a liquid.
Filtration
Give the name of a method of separating a soluble solid from a liquid.
Evaporation.
The liquid will evaporate whilst the crystals of the solid begin to form.
Which method of distillation would you use to separate a mixture of liquids with similar boiling points.
Fractional distillation.
