chemistry-unit 2

shielding

when the inner core electrons block or reduce the positive pull of the nucleus on valence electrons

electro-negativity

how strongly an atom attracts shared electrons toward itself in a chemical bond.

atom-radius

the distance from the center of the nucleus to its outer-most shell

ionization energy

the minimum energy required to remove an electron from an atom

period

a horizontal row on the periodic table

group

a vertical column on the periodic table

wich way does the atomic radius get bigger on a periodic table

down and left

wich way do atoms have more pull (electronegativity)

right and up

which element has the most electronegativity

fluorine

wihch way has more ionization energy

right and up

what makes up an ionic compound

metals and non metals

how are ionic compounds connected

• One atom gives away an electron and becomes positively charged (a cation).

• Another atom takes that electron and becomes negatively charged (an anion).

• Because opposites attract, the positive and negative atoms lock tightly together.

properties of an ionic compound

high melting point, strong repeating solid crystal structure at room temperature (lattice structure), very brittle, can conduct electricity when dissolved or liquid, transfer of electrons forming cations and anions.

what makes up a covalent compound

2 or more non metals

how do covalent compounds stay together

by covalent bonds (bonds where the atoms share electrons)

rules for naming covalent electrons

• Name the first element using its full element name, adding a prefix only if there is more than one atom (never use mono- on the first element).

• Name the second element by shortening its name and adding the ending -ide.

• Use Greek prefixes to show how many atoms of each element are (for both elements)

properties of covalent bonds

made of only non metals, shares electrons, low melting point (melts easily), dissolves with molecules intact, when together, forms individual molecules.