Topic 1- Atomic structure & the periodic table Flashcards
What is an atom?
The smallest part of an element that can exist.
What is an element?
An element is a substanve of only one type of atom.
What is a compound?
Two or more elements chemically combined in fixed proportions.
Do compounds have the same properties as their constituent elements?
No, they have different properties.
What is a mixture?
A mixture consists of two or more elements or compounds not chemically combined together.
Does a mixture have the same chemical properties as it’s constituent materials?
Yes, it has the same chemical properties.
What are the 5 methods through which mixtures can be seperated? Do they involve chemical reactions?
Filtration, crystallisation, simple distillation, fractional distillation and chromatography. They DO NOT involve CHEMICAL REACTIONS!
Describe the plum pudding model.
The atom is a ball of positive charge with negative electrons embedded in it.
Describe the Bohr/ Nuclear model. How did it come about?
ALPHA PARTICLE EXPERIMENT CONCLUSIONS:
* The mass of the atom was concentrated at the nucleus.
* The nucleus was positively charged.
THE NUCLEAR MODEL:
* Electrons orbit the nucleus at specific distances. The nuclear model came about throough the alpha particle scattering experiment.
What did James Chadwick do?
He provided evidence for the existence of neutrons in the nucleus.
State the relative masses and relative charges of the proton, nuetron and electron.
RELATIVE MASSES:
* Proton- 1
* Neutron- 1
* Electron- Very small
RELATIVE CHARGES:
* Proton- +1
* Neutron- 0
* Electron- -1
What is the radius of an atom?
0.1 nm
What is the radius of the nucleus?
1 x 10^-14 of that of an atom.
What do atoms of the same element have nn common?
The same number of protons in the nucleus.
What is an isotope?
- Isotopes are atoms of the same element that have a different number of neutrons
- Isotopes of he same element have the same elctronic structure, so have the same chemical properties.
What are ions?
Ions are charged particles. They are formed when an atoms loses/gains electrons.
What are the properties of metals?
- High boiling point
- Conduct heat & electricity
- Shiny
- Malleable
- High density
What are the properties of non-metals?
- Low boiling/ melting pint
- Do not conduct heat/ electricity (except graphite)
- Dull
- Brittle, not malleable
- Low density
What is formed when a metal reacts with a non–metal?
An ionic compound.
What is formed when a non–metal reacts with a non-metal?
A molecular compoound containing covanlently bonded atoms.