Photo of concept map of chemical reactions. At the top is a circle labeled Chemical Reactions. The top circle leads to a second row of three circles. The left circle is empty with a question mark. The middle circle is labeled exothermic reactions. The right circle is empty with a question mark. The middle and right circles lead to a third row of two circles. The left circle on the bottom row is empty with a question mark. The right circle on the bottom row is labeled absorbed.