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to change directly to a gas from a solid, without going through the liquid phase
burning, when a substance reacts quickly with oxygen and gives out energy
a compound that contains hydrogen and carbon only
which is the most abundant gas in the earth's atmosphere?
what percentage of nitrogen is there in air?
what percentage of oxygen is there in air?
what percentage of argon and other gases including carbon dioxide is there in the air?
what kind of gas is argon gas?
a noble gas
what is the word equation for photosynthesis?
carbon dioxide + water + light -> glucose + oxygen
what is the word equation for respiration?
glucose + oxygen -> carbon dioxide + water + energy for life
what is the word equation for combustion?
fuel + oxygen -> carbon dioxide + water + heat/light energy
how are hydrocarbons such as methane gas and oil formed?
when dead sea creatures like plankton decay and the carbon inside them join with hydrogen atoms under high pressure and temperature
forms when carbon dioxide reacts with a water molecule
what is the name of the compound that is used by shell fish to form the hard shell?
calcium carbonate
what is limestone made from?
dead shell fish cemented together under pressure