Atomic Structure

what is an element?

a substance consisting of one type of atom

what is a compound?

a substance consisting of two or more elements chemically bonded

what is the ending for 2 elements and one is oxygen, halogen or sulfur?

-ide

what is the ending when there are 3 or more elements and one is oxygen?

-ate

what is the ending when there are 3 elements or more and 2 of them are hydrogen and oxygen?

-hydroxide

what are the features of democritus’ atom model?

• indivisible

• there are different types

what are features of thomson’s model?

• electrons embedded

• solid atom of positively charged matter

what are the features of rutherford’s model

• positive middle

• electrons around the edge

• mostly space in atom

what are the features of bohr’s model?

• electrons are in shells

• positive nucleus

what are the features of chadwick and Rutherford’s atom model?

• nucleus is made of protons and neutrons

• electrons in shells

why might the product of a reaction have a larger mass than the reactants

gas from the atmosphere binds to the product

why might the product of the reaction have a smaller mass than the reactants

some of the products became a gas and escaped the atmosphere

what is the radius of an atom?

0.1nm or 1×10^-10

what is the radius of the nucleus?

1×10^-14

how many electrons are on the first shell?

2

how many electrons are on every other shell than the first one?

8

what is the atomic number?

the number of protons

what is the atomic mass?

number of protons + neutrons

what is an isotope?

atoms of the same element (same number of protons) and different number of neutrons

what is a mixture?

2 or more elements or compounds that are not chemically bonded

what does chromatography do?

separates mixtures which have different solubilities

what does filtration do?

separates an insoluble solid from a mixture of a solid & liquid

what does crystallisation do?

separated a solute from a mixture of a solid and liquid

what does simple distillation do?

separates a solvent from a mixture of a solid and liquid

what does fractional distillation do?

separates a liquid from a mixture of liquids using a fractional column

how were old periodic tables arranged?

by atomic weight

what is a solvent?

the liquid that a solute is in

what is a solute?

a soluble subtance

how are modern periodic table arranged

in order of atomic number (number of protons)

what are groups?

elements with similar properties in columns, having the same number of electrons in the outer shell

what are some physical properties of transition metals?

• hard

• high melting points

• high density

• good conductors of heat & electricity

• silver or brown