i'll give a brainiest.

Which of the following is always a reactant in a combustion reaction? oxygen nitrogen hydrogen carbon

The diagram below shows the different phase transitions that occur in matter. which arrow represents the transition in which dew is formed?

Consider the following reaction at equilibrium: c(s)+h2o(g)⇌co(g)+h2(g) predict whether the reaction will shift left, shift right, or remain unchanged upon each of the following disturbances. a) c is added to the reaction mixture. b) h2ois condensed and removed from the reaction mixture c) co is added to the reaction mixture d) h2 is removed from the reaction mixture.