True or false: ionic bonding involves the shareing of electrons, oxide ions have a 2+ charge , electrons have a negative charge , a hydrogen molecule is held together by a strong covalent bond between two hydrogen atoms, a covalent bond is a shared pair of electrons.

the density(ratio between mass and volume as m/v) decreases from top to bottom in periodic table group as the size increases and nuclear charge decreases. but in periods density increases from left to right as atom size decreases and nuclear charge increases.

conduction is the transfer of thermal energy (heat in transfer) due to collisions between the molecules in the object. collisions between adjacent atoms and molecules transfer kinetic energy from the warmer to the cooler object. the objects must be in physical contact.