Chem year 10 for exam Flashcards
Periods
Across: number of electron shells
Groups
Down: number of valence electrons
Isotopes
Atoms of the same element, different number of neutrons in the nucleus
Group 1 elements
Alkali metals
Group 2 elements
Alkali earth metals
Group 17 elements
Halogens
Group 18 elements
Noble gases
Mass number
Number of protons and neutrons
Atomic number
Number of protons
Characteristics of metals
-Solid at room temperature
-Polished to produce a high shine/lustre
-Good conductors of electricity
-Malleable
-Can be made into a wire; ductile
-Usually melt at high temperatures (mercury is the exception)
Characteristics of non-metals
-Cannot be polished to produce a shine
-Brittle; shatter when hit
-Cannot be bent into shape; not malleable
-Usually, poor conductors of electricity and heat
-Usually melt at low temperatures
-Many are gases at room temperatures
The number of electrons per shell
2n^2
Flame test: ground state
Lowest energy state of an atom
Flame test: excited state
Highest energy state of an atom
Positively charged ions
Cations
Negatively charged ions
Anions
Electrostatic attraction
The attraction between two oppositely charged bodies
Covalent bond
A shared pair of electrons holding two atoms together