Which of the following is the best description of convection? a. heat transfer in a gas or liquid by the circulation of currents from one region to another b. the emission of energy in the form of rays or waves that are able to travel through empty space c. the process of changing from a gas to a liquid or from a liquid to a gas d. the transmission of heat through a medium without the motion of the medium

1)each group 16 element has how many valence electrons? ( )4 ( )6 ( )8 ( )16 2)how many dots appear in the dot structure for calcium ion, ca2+? ( )zero ( )one ( )two ( )eight 3) which of the following atoms forms a cation to obtain an octet of outer shell electrons? ( )magnesium ( )oxygen ( )fluorine ( )helium 4) an al3+ ion contains 13 protons and 10 electrons. ( )true ( )false 5) valence and non-valence electrons are represented in lewis dot structures. ( )true ( )false

The variability in marine salinity between habitats does not impact the fish living there. select the best answer from the choices provided t f

Ahydrogen atom has 1 electron. how many bonds can hydrogen form? a) 1 b) 2 c) 3 d) 4 e) 5