Unit 2 Flashcards
What is an element
A substance that only contains only one kind of atom
What is the row in the periodic table called
Period
What is a compound
A compound contains atoms of different elements joined together where the atoms are chemically combined
What is an isotope
Atoms of the same element with different numbers of neutrons
How do isotopes become radioactive
When the nucleus is unstable sooner or later the atoms breakdown or decay is giving out radiation in the form of rays and tiny particles as well as large amount of energy
What is half life
The half life of an isotope refers to the time it takes for one half of the sample to decay
What are the uses for radiation
Checks for leaks in pipes. This is done by adding a radio isotope to the oil or gas .at the leak ,the radiation is detected using instruments . radio isotopes used in this way are called tracers.
In cancer treatment. Radio isotopes can cause cancer but can also cure it. Using radio therapy the radio isotopes will decay and give out rays that can kill cancer cells. These rays Will be aimed exactly at the cancer cells.
To find the age old remains. A tiny percentage of a living thing contains carbon 14 atoms when living things dies no longer takes in new carbon atoms but existing carbon-14 atoms decay over time we can measure the faint radiation from them
What does electronic configuration mean
The arrangement of electrons in an atom
What are Vallency electrons
All the elements in a group have the same number of electrons in their outer shells
What is a group number
The same number of outer shell electrons
What is a period number
How many shells there are
