Chemistry Paper 1 Flashcards
(19 cards)
Define element
a substance made from one type of atom. e.g oxygen.
define compound?
a substance made from one more or types of atoms chemically bonded together e.g. water
define mixture?
a substance made from elements or compounds but not chemically bonded together.
How do you get pure water from a salt soltution e.g. sea water.
You use distillation. Heat up the solution so it evapourate and condise it back to liquid leaving salt behind.
Describe states of matter?
Solid - vibrates at fixed position regular arrangement cannot be compressed.
liquid - have no regular arragement and are able to move past each other cant be compressed.
Gas - gases are far apart and move randomly and fast and have can be compressed.
What did ruthersford discover about atoms and how?
He discovered the nucleus by firing alpha particales (positive charge) through a thin gold leaf. Most went straight through but some were deflected. this showed that ever atom is mostly empty space but has a small positive charge in the centre of the nucleas
what are periods in the periodic table?
Periods are rows/lanes in the periodic table.
in periodic table what is the top number of the element?
Atomic number equal to number of eletrons unless ionized
in periodic table what is the bottom number of the element?
atomic weight
how to find number of neutrons in a element is periodic table?
after rounding atomic weight to nearest number minus it from atomic number to find number of neutrons.
what do all elements in same period share in the periodic table?
same number of enegry shells.
what do groups have the same in periodic table?
Same number of eletrons in there outer most shell.
what does group number equal?
ground number = number of valence eletrons
what is a group in the periodic table
a group in peridic table is a column in it.
what do periods show?
number of shells.
what does valence number mean?
these are the eletrons avaible for reactions and bond formations.
what is magnesiums ion if its in group 2?
mentals donate their outer eletron to leave an empty outer shell magnesium being in group 2 means it donates 2 of its eletrons that it must do when bonding this forms the ion mg ^ 2 + because it lost 2 eletrons.
What is ionic bonding?
non metals accept eletrons from metals to form ions.
covalent bonding?
non metals share eletrons to gain full outer shells.
