chem Flashcards
(43 cards)
Is potable water pure
no
what is simple distillation
separation of liquids/solution by evaporation then condensation
What state is a substance with a m.p of 567 and b.p of 765
Solid
What state is a substance at room temp with a m.p of -119 and b.p of -70
Gas
What state is a substance at room temp with a m.p of 10 and b.p of 145
Liquid
Which substances have the strongest bonds between particles
Highest M.P and B.P
What states can metal be at room temp
Solid, liquid
How many metals are liquid at room temperature
1 (mercury)
2 types of pure substances
Pure compounds, pure element
What is a compound
2 or more elements chemically bonded together
How do you know if a substance is pure
Distinct m.p / b.p
How do you know if a substance is a mixture
Freezes / melts over temp range
In chromatography, why is start line drawn in pencil
It’s insoluble in water
How do you know which is least soluble
Furthest traveled up
How to find rf value + below or above 1?
Didtance moved by chemicals (dye) / distant moved by solvent
How to get solid crystals from mixture
Evaporating basin
Where do you get water from (man made)
Reservoir
What does screening do
Removes leaves and branches
What does sedimenting do
Let’s solids sink to the bottom of the tank
2 things Dalton got wrong
Atoms can’t be broken down smaller - now know abt neutrons, protons + electrons
Atoms of same element are same - isotopes
How do you find how many electrons are in a atom
Mass number - atomic (proton) number
Electronic configuration (max for gcse)
2.8.8.2
Group number =
Number of electrons on outer shell
