22.1. Isotopes http://www.ck12.org
Review
Questions
- What do different isotopes of a given element have in common? How are they different?
- What is the element name of the atom represented by^23292 X?
- How many protons and how many neutrons does the nucleus in problem #2 have?
- Using the following data, calculate the atomic weight of magnesium.
Magnesium-24 = 78.70%
Magnesium-25 = 10.13%
Magnesium-26 = 11.17%- nucleus:The nucleus is the very dense region consisting of protons and neutrons at the center of an atom.
- neutron:A neutron is an uncharged elementary particle that has a mass nearly equal to that of the proton and
is present in all known atomic nuclei except the hydrogen-1 atom. - nucleons: A nucleon is either of the subatomic particles, the proton and the neutron, constituting atomic
nuclei. - nuclides:An atomic nucleus specified by its atomic number and atomic mass.
- atomic number:The number of positive charges or protons in the nucleus of an atom.
- mass number:The mass number (A), also called atomic mass number or nucleon number, is the total number
of protons and neutrons (together known as nucleons) in an atomic nucleus. - isotopes:One of two or more atoms having the same atomic number but different mass numbers.
- atomic weight:The average mass of an atom of an element, usually expressed relative to the mass of carbon
12, which is assigned 12 atomic mass units.