Which elements are found in all four components of earth ? ?

How many moles are in 250 grams of tungsten (w)? * 4.4x10^23 moles 4.2x10^23 moles 0.7 moles 1.4 moles

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.

Consider the reduction reactions and their equilibrium constants. cu+(aq)+e−↽−−⇀cu(s)pb2+(aq)+2e−↽−−⇀ pb(s)fe3+(aq)+3e−↽−−⇀fe(=6.2×108=4. 0×10−5=9.3×10−3 cu + ( aq ) + e − ↽ − − ⇀ cu ( s ) k =6.2× 10 8 pb 2 + ( aq ) +2 e − ↽ − − ⇀ pb ( s ) k =4.0× 10 − 5 fe 3 + ( aq ) +3 e − ↽ − − ⇀ fe ( s ) k =9.3× 10 − 3 arrange these ions from strongest to weakest oxidizing agent.