1.1.1 - Atoms Flashcards
What is the relative mass of:
- An electron?
- A proton?
- A neutron?
- Negligable.
- 1
- 1
What is the relative charge of:
- An electron?
- A proton?
- A neutron?
- 1 -
- 1 +
- 0
Describe the distribution of mass and charge within an atom.
Most of the mass is concentrated in the nucleus where the protons and neutrons are, giving it a slight positive charge. The electrons surround the attom in shells, giving it a slight negative charge and a negligable mass.
Describe how protons and neutrons contribute to the atomic number and mass number of an atom.
The more protons = The higher the atomic number.
The more protons and neutrons = The higher the mass number.
Look at the Periodic table. How many protons, neutrons and electrons are there in hydrogen?
1 proton
1 neutron
1 electron
Look at the Periodic table. How many protons, neutrons and electrons are there in bromine?
35 protons
45 neutrons
35 electrons
Define the term ‘isotope’.
Isotope - Atoms of the same element with same number of electrons and protons but different numbers of neutrons and therefore have different masses.
Which atom is used as the standard measurement of relative masses?
The carbon 12 atom (12C).
Define the term ‘relative isotopic mass’.
Relative isotopic mass - the mass of an atom of an isotope compared with 1/12 of a carbon-12 atom.
Define the term ‘relative atomic mass’.
Relative atomic mass - the weighted mean mass of an atom of an element compared with 1/12 of a carbon-12 atom.
When do scientists use the term ‘relative molecular mass’:
- For simple molecules?
- Or for compounds with giant structures?
Relative molecular mass - for simple molecules.
When do scientists use the term ‘relative formula mass’:
- For simple molecules?
- Or for compounds with giant structures?
Relative formula mass - for compounds with giant structures.
