1What are the three key ideas of Dalton's atomic theory?
1. Atoms cannot be created, destroyed, or divided.
2. Atoms of the same element are identical.
3. Atoms combine to form new substances.
2What is an atom?
A tiny particle that makes up matter.
3When are new substances formed?
When atoms combine together they form new substances.
4When can a scientific model can be changed or replaced?
When new experimental evidence improves our understanding.
5What is the mass and charge of a proton?
A proton has a relative mass of 1 and a charge of +1.
6What do all atoms of the same element have in common?
Number of protons (atomic number)
7What is the mass and charge of an electron?
An electron has a negligible mass and a charge of -1.
8What subatomic particles are in the nucleus of an atom?
Nucleons: protons and neutrons.
9How do you calculate the number of neutrons in an atom?
Mass number - atomic number (or number of protons)
10What subatomic particles are atoms made up of?
Protons, neutrons and electrons
11What is the mass and charge of a neutron?
A neutron has a relative mass of 1 and a charge of 0.
12How do you determine the number of electrons in an atom?
It is the same as the atomic number (number of protons)
13Why are atoms electrically neutral?
They have the same number of electrons and protons.
14Which subatomic particle is not found in the nucleus of an atom?
Electron
15What is the nucleus?
Central part of an atom.
16Define atomic number
The number of protons (in the nucleus of an atom).
17Define mass number
Total number of protons and neutrons (nucleons) in the nucleus of an atom.
18Where is most of the mass of an atom?
The nucleus
19Compare the size of the nucleus to the atom
The nucleus of an atom is very small compared to the overall size of the atom.
20Why do chlorine and copper not have whole numbers for their atomic mass?
Because of isotopes
21What are isotopes?
Atoms of the same element which contain the same number of protons but different numbers of neutrons.
22True or False: Isotopes display different chemical characteristics.
False!
Isotopes have the same chemical characteristics.
23What determines the chemical characteristics of an atom?
The number of electrons in the outer shell.
24How can you find the number of electrons in a neutral atom?
The number of electrons is equal to the number of protons, which is the atomic number.
25What is the relative atomic mass in the periodic table?
Relative atomic mass is an average of all isotopes of an atom.
26State two pieces of information required to calculate the relative atomic mass of an element.
Mass number of each isotope
The percentage abundances of each isotope
27How would you calculate the relative atomic mass of an element?
(percentage of isotope A x mass of isotope A) + (percentage of isotope B x mass of isotope B)/100
28In terms of isotopes, what is abundance?
Abundance is the amount of each isotope present in a sample of an element.