UNIT 1 - atomic structure Flashcards
what elements have similar chemical qualities?
elements in the same group in the periodic table
what are the alkali metals features?
-very reactive
-soft (can be cut with a knife)
-stored under oil
-react with water to form an alkaline solution
-reacts with oxygen to form metal oxides
what are the transition metals features?
-hard and dense
-less reactive than the alkali metals
-used in catalysts
-form coloured compounds
what are the halogens features?
-diatomic elements
-all toxic
-fluorine added to toothpaste to prevent decay
-chlorine added to swimming pools to sterilise them
-iodine used to treat wounds
what are the noble gases features?
-the least reactive of all of the elements
-do not react at all
what are elements made up of?
just one type of atom
what are atoms made up of?
Protons, neutrons, electrons
what is the center of an atom called?
it is called the nucleus
what does the nucleus of atom contain?
protons and neutrons
what is the charge of a atoms nucleus?
positive
where are the negatively charged electrons found in the atom?
orbiting outside the nucleus
why are atoms neutral?
because the number of positively charged protons is equal to the number of negatively charged electrons
describe a proton.
-has a positive charge
-has a amu of 1
-is located in the atoms nucleus
describe a neutron.
-has a neutral charge
-has a amu of 1
-is located in the atoms nucleus
describe an electron.
-has a negative charge
-has a amu of nearly 0
-is located orbiting around the atoms nucleus
what is the atomic number?
it is the number of protons and electrons
where is the atomic number found?
it is found at the bottom of the elements symbol
what is the mass number?
it is the atomic number + the number of neutrons
where is the mass number found?
it is found at the top of the elements symbol
how would you find the number of neutrons if you have the mass number and the atomic number?
mass number - atomic number
