How long will the plant have been dead when 87.5 percent of its C-14 has become N-14? After 1 half-life After 2 half-lives After 3 half-lives After 4 half-lives
50
25
12.5
6.25
percent of 14C remaining

What type of reaction is shown below? check all that apply. 2h2o2 → 2h2o + o2 synthesis decomposition combustion

How does a catalyst increase the speed of a reaction? a. the catalyst eliminates the activated complex stage, allowing products to form immediately. b. the catalyst lowers the energy level of the reactants, making it easier for them to react. c. the catalyst makes it easier for the activated complex to form, lowering the activation energy. d. the catalyst raises the energy level of the products, making the reaction finish sooner. reset next

What is the most common reason for matter changing its state?