Elements, compounds, mixtures & Moles Flashcards
(31 cards)
What is relative atomic mass?
Ar = mass of element
What is relative formula mass?
Mr = mass of substance
How to calculate Mr?
Add all Ar from all elements in mixture.
What is empirical formula?
Simplified chemical formula to smallest whole number ratio.
What’s a balanced chemical equation?
Shows reaction, same number of atoms and mass in both sides.
What’s a pure substance?
Substance that consist of only one element?
How does melting point determine if it’s pure or not?
Melting point is lower, and melting in range of temperature means it’s IMPURE.
What’s a solution?
A substance that has dissolved in another.
Different components of the solution?
Solute: Substance which dissolves
Solvent: Where the solute dissolved in
What’s filtration?
Separates, insoluble substance form solution.
What’s simple distillation?
Boils lower melting point substance first, leaving other behind.
How does fractional distillation work?
Separates 2 or more substances from mixture in liquid state (each substance has different boiling point).
How does chromatography work?
Mobile phase moves through stationary phase, separates coloured substance.
What’s a period (periodic table)?
Horizontal row
What’s a group (periodic table)?
Vertical column
What’s an ion?
A charged particle, molecule or atom.
What’s ionic bonding?
One electron goes to other substance. Linking them ionically. (Non-metal = Metal)
What’s covalent bonding?
Shared pair of electrons. (Non-Metal - Non-Metal)
What’re polymers?
Group of smaller monomers (monomers) joined together (linked up).
What’re metallic bonds?
Metals loose electrons forming sea of electrons which keep all metal ions together.
Why some substances conduct electricity?
Because they have free electrons that can move.
How big are nano particles?
1-100 nm (nanometers)
How do you write the formulae of metal elements?
Always in the empirical formula, because they’re in giant latices.
What is conservation of mass?
Mass is never gained or lost in a chemical reaction (closed system).
