PLEASE HELP, I WILL MARK BRAINIEST what determines an atom's reactivity?

#1. how many protons the atom contains
#2. how many energy levels the atom contains
#3. whether the atom is a metal or a non-metal
#4. how many valence electrons the atom contains

Researchers want to use edna to look for an invasive species in the water which of the steps would be likely do last

Cells must be in osmotic equilibrium with their surroundings environments because if they swell or shrink thier membranes will rupture

1. an enzyme is considered a(n) because it speeds up a chemical reaction without being used up.2. in a catalyzed reaction, a reactant is often called a(n) . an enzyme is specific because the shape of its matches only particular reactants.4. an enzyme speeds up reactions by lowering the . the between an active site and its substrate often strains bonds and the reaction proceed.6. a( , which is often a vitamin, binds to an enzyme and plays a role in catalysis.7. high temperatures or changes in ph can an enzyme, causing it to lose its shape and biological activity.