What is the change in enthalpy for a reaction if the reactants have 270 kJ of energy and the products have 150 kJ of energy

Asap! how do you lengthen a pattern piece? (family and consumer science, sewing)

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Label a-f based on the table using c for concentrated and d for dilute