Which group of elements is generally unreactive? O A. Noble gases O B. Halogens O C. Alkali metals D. Nitrogen family

Layers of rock containing fossils, like the layers illustrated here, are most likely composed of rocks.

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.

Fill in the coefficients that will balance the following reaction: a0cr2(so4)3 + a1agno3 -> a2cr(no3)3 + a3ag2so4