Atomic structure and the periodic table-Chemistry paper1 Flashcards
Define atom
The smallest part of an element that can exist.
Define atomic number
The total number of protons in an element.
Define a compound
A substance which has 2 or more elements chemically bonded with each other.
Define element
An element is a substance that only contains one type of atom and each atom has the same number of protons.
What is meant by the term ion?
An ion is a group of atoms that has lost or gained electrons to become charged.
What is meant by the term isotope?
An isotope is a group of atoms that have the same number of protons but have a different number of neutrons.
What is meant by the term mixture?
A mixture is a substance that contains 2 or more elements that are not chemically bonded to each other.
Define relative atomic mass
The number of protons and neutrons added together in an atom.
What do the numbers represent on subatomic particles?
e.g if given Na the number on top(largerone) represents the relative atomic mass and the one on the bottom(smaller one) represents the atomic number(proton amount)
What experiment did Ernest Rutherford carry out and what did it do?
He carried out the gold foil experiment, this was where he fired postively charged alpha particles at a thin sheet of gold foil.
What did niels bohr find out?
He dtermined that electrons were found in shells
He also found out that protons were found in the nucleus of each atom.
What did James Chadwick find out?
He discovered particles with a mass but no charge(neutrons)
What are all of the properties of the alkalis?
- they are soft and get softer as you go down the group
- they all have low melting points
- they all have low densities and this increases as you go down the group.
Why doe reactivity increase the further down group 1 you go(the alkalis)
- The outer shell electrons are further away from the nucleus
This means that the force of attraction between the nucleus and the outer shell electron decreases
This means that the electron can be lost more easily.
What are the physical properties of group 7(the halogens)
They exist as simple diatomic molecules, each atom is bound by a single covalent bond to one other atom.
Why do the melting and boiling points increase as you go down group 7 (the halogens)
This is because the atoms are larger,
Intermollecular forces increase between the atoms
More energy is required to overcome them.
What is one thing that group 1(alkalis) have in common
They all contain one electron on their outer shell.
What are the results of different chemical reactions using an element from group 1?
water?
Oxygen
Chlorine?
1.Reactions with water form a metal hydroxide(sodium +water to sodium hydroxide + hydrogen)
2. Reactions with oxygen form a metal oxide (sodium+oxygen tosodiumoxide)
3.Reactions with chlorine form a metal chloride(sodium+chlorine to sodiumchloride)
What are observations of these reactions when the element is placed in water(lithium,potassium,sodium)
- Lithium-Fizzes steadily,slowly becomes smaller until it disappears.
- Sodium-Fizzes rapidly,melts to form a ball, quickly becomes smaller till it disappears
3.Potassium-Burns violently with sparks and a lilac flame, quickly burns to form a ball disappears rapidly odten with a small explosion.
Why does reactivity of group 7 decrease as you go down the group?
- The outer shell electrons are further away from the nucleus
The force of attraction between the nucleus and the outer shell electrons decrease
An extra electron required to make the atom stable is more difficult for the atom to get.
What are the results of different chemical reactions within group 7 (halogens)
metals?
non metals?
displacement reaction?
- Reactions with metals, they form salts(sodium+chlorine to sodium chloride
- Reactions with non metals, reacts with hydrogen to form a hydrogen halide(hydrogen+chlorine to hydrogen chloride)
- Displacement reactions, more reactive halogens displace less reactive halogens when reacting.
Who and when was the first periodic table publshed and by who?
First published in 1969 and was published by Dimtriv Mendeleev
What are the properties of the transition metals?
- They all conduct electricity in solid and liquid states.
- Shiny when freshly cut
(compared to other metals most transition maetals are/have)
3.Higher melting points
4.Higher boiling points - Greater strength
- Greater hardness
What are the results of different reactions of transition metals?
1.) water+oxygen
2.) Halogens
3.) coulour of compound they form?
1.Reaction with water and oxygen, react slowly or not at all(less reactive than elements from group1)
2. Reaction with halogens, Some halognes react slowly woth halogens
3. compound formation,Transition metals form coloured compound most othe elements form white compunds.
What are the physical and chemical properties of metals and non metals?
- Most metals have high melting and boiling points
- Most non metals have low melting and boiling points.
