Isotopic Abundance & Periodic table groups/periods Flashcards
What is the mass of all elements based on?
the isotope of carbon, that has the mass number 12, is assigned a mass of exactly 12 atomic mass unit (amu), and the masses of all other atoms are given relative to this standard.
Group 1a
The elements of group 1A, with the exception of hydrogen are called alkali metals. The word alkali means basic, and these metals form bases upon reaction with water. For example sodium reacts with water to form sodium hydroxide which is a strong base.
group 2a
The elements of group 2A are called alkaline earth metals since they form bases upon reaction with water, and are also found in high abundance in the earth’s crust.
7a
The elements of group 7A are called halogens. The word halogen means salt maker. These elements form salts (ionic compounds) upon reaction with metals. For example, the reaction of chlorine with sodium produces sodium chloride (table salt).
8A
The elements of group 8A are called noble gases. Under normal conditions, these elements exist as monoatomic gases.
other metals
other metals:
- not as reactive as group 1 and 2
- quite common
metalloids
metalloids
- properties of both metals and non-metals
- poor conductors and brittle
other non-metals
other non-metals
- not halogens or noble gases
- most common elements in tissues of living organisms
noble gases
noble gases
- very unreactive
- no natural reactions (can be artificial)
- exist naturally as monoatomic gases
Inner transition metals or rare earth elements
Since these series begin with the elements lanthanum (La) and Actinium (Ac), they are known as Lanthanides and Actinides. chemists had difficulty separating them from one another (lanthanides). they are used in advanced batteries in hybrid cars. Actinoids have no stable isotopes and are all radioactive. All elements beyond uranium are not naturally occurring and can only be produced artificially.
