C1 Flashcards
What is the relative charge of:
a) a proton
b) an electron
c) a neutron
a) proton= +1
b) electron= -1
c) neutron= 0
What are the relative masses of the three sub-atomic particles?
- proton= 1
- neutron= 1
- electron= virtually nothing
What is the radius of an atom and the nucleus of an atom?
- atom= 1 x 10-10
- nucleus= 1 x 10-14
What is an element?
An element is substance made up of only one type of atom
What is an ion?
an ion is an atom or element that has lost or gained electrons, therefore giving it a charge
True or False? Elements only contain atoms with the same number of protons.
True
What does the relative mass number of an element tell us?
the total number of protons and neutrons
What does the relative atomic number of an element tell us?
the number of protons
Define an isotope
An isotope is a form of an element with the same number of protons but a different number of neutrons
Define a molecule
A molecule is two or more atoms, held together by chemical bonds
What is the difference between mixtures and compounds?
A compound is two or more different elements that are chemically combined in fixed proportions bonds whilst a mixture is two or more elements that are not chemically joined
Before the discovery of the electron, what were atoms thought to be?
Tiny spheres that could not be divided
What did the discovery of the electron lead to and what did this model suggest?
The plum pudding model:
the atom is a ball of positive charge with
negative electrons embedded in it
Which scientist did the alpha particle scattering experiment and what conclusions could be made from the experiment?
Ernest Rutherford
- the mass of an atom in concentrated in the centre
- the atom is mostly empty space
- the nucleus was charged
What replaced the plum pudding model and how did Neil Bohr adapt the model?
The nuclear model
he suggested that electrons orbit the nucleus at specific distances; his theoretical calculations agreed with experimental observations