Which of the following is a sign a chemical reaction has occurrd

The half-life of carbon-14 is 5730 years. therefore, 5730 years after being cut from a tree, a piece of wood will have 50.0% of the carbon-14 that it had originally.

Which description explains the role of activation energy in a chemical reaction? A. It provides useful energy that is released in an exothermic reaction. B. It stops the products from being formed from the intermediate state. C.

The chemical properties of a substance can only be observed when it is changed into a different substance T F

What is the first thing you notice about a person?.-_-

What is the percent of O in Cr2O3?

When is Ksp determined for a system?

What is the average surface temperature of Uranus

Consider the following statements. A. Molecules of hot water have less kinetic energy than those of cold water. B. For most solids, solubility increases when temperature increases. C.

Which describes the fourth state of matter known as plasma? A It is a liquid containing nuclei and electrons. B It is a gas containing nuclei and electrons. C It is a liquid containing electrons created by fusion.

The process of using dna to produce complementary rna molecules is called