Activation Energy is A. the heat released in a reaction. B. an energy barrier between reactants and products. C. the energy given off when reactants collide. D. generally very high for a reaction that takes place rapidly

You started with 64 g of a radioactive substance. If you have 4.0 g of that substance left, then how many half-lives have elapsed? a. 2 b. 3 c. 4 d. 5

A nondirectional alternative hypothesis claims that no difference will be found between the research variables. a. True b. False

The primary structure of a protein determines its secondary and tertiary structures. arrange these steps in the folding of a globular protein.

What is one thing chemical properties and physical proprieties of matter have in common

What is the molecular formula of a molecule that has an empirical formula of CH and a molecular mass of 78.11 g Show all of your work

Every water molecule has two hydrogen atoms bonded at one oxygen atom. This fact supports the concept that elements in a compound are

What is the mass of 9 atom (s) of copper in grams?

Andy has two samples of liquids. Sample A has pH of 4, and sample B has a pH of 6. what can Andy conclude about these two samples? Sample A is a neutral b alkali c acidic Sample B is a neutral b alkali c acidic

How does a lone pair contribute to molecular shape? A. It is too small to affect the molecule's shape. B. It takes up space like an "invisible" atom. C. It forces the molecule into a tetrahedral shape. D. It lets the bonding pairs spread out more.

The are of a rectangle is 12 in^2. what is the area in cm^2. there are 2.54cm in an inch.