unit 11 chem test

Ionic properties

Crystal lattice, conductive when dissolved in water, and high difference in electronegativity between atoms in bond

Covalent properties

Molecules, not conductive, low difference in electronegativity between atoms in a bond

Metallic properties

Ductile and lustrous, conductive, and low difference in electronegativity between atoms in bond

How do ionic bonds form

Electron is transferred and ions are form which attract

How do covalent bonds form

Electrons are shared between atoms

How do metallic bonds form

Electron sea (electrons move freely)

Explain energy changes in the formation of a covalent bond at the subatomic level

⬇potential energy ⬆stability ⬇reactivity ⬆attraction ⬇p. spacing

Combustion

Hydrocarbon+oxygen➡carbon dioxide+water+Energy

Explain at the particle level what causes a reaction to occur

⬆energy added, bonds between atoms break, ⬆p. spacing, ⬆p. velocity, ⬆ # & F of collisions, therefore p. form new bonds

Define and explain activation energy at the particle level

Energy added which breaks bonds between particles.

Exothermic reaction

Combustion, release heat (flame, sparks, popping sounds, steam)

Define enthalpy

Energy of a reaction kJ/mol (change in E from before to after)

Bond energy definition

E to break a bond, always endothermic, kJ/mol

Potential energy definition

Ability to react, E of position (p. spacing)

Empirical formula definition

Smallest whole number ratio formula

Molecular formula

Actual formula, not necessarily the smallest whole number ratio

Identify and apply that energy is conserved

In a closed system, the total amount of energy does not change, it transforms.