Unit 3- atoms and element Flashcards
What is an atom
smallest particles of matter, that we cant break down further by chemical means
What is an element
A substance that cant be split into anything simpler, in a chemical reaction
What is the relative mass of election compare to proton and neutron
almost nothing ( 1/1840)
How to identify an atom
By its proton number
Why element has no charge in overall
They have same number of proton and electron
What is nucleon number
Total number of protons and neutrons in the nucleus of an atom
What are isotopes
Isotopes are atoms of the same element which have the same proton number, but a different nuclon number.
What happens if the nucleus is not stable
It gives out radiation
Use of radioisotopes
Check for leaks, treat cancer, kill bacteria
What is the maximum number of electrons can there be in the first outer shell
2
What is the maximum number of electrons can there be in the second outer shell
8
General properties of metal
Good conductor of heat and electricity high melting and boiling point hard malleable ductile shiny sonorous high density form positive ions when they react react with oxygen to form basic oxides
General properties of non-metals
Poor conductor of heat and electricity low melting and boiling point, brittle dull low density form negative ions when they react react with oxygen to form acidic oxides
