Which is a physical change?

A)

burning wood

Eliminate

B)

rusting metal

C)

cooking an egg

D)

freezing water

Where do new root cells from? A. behind the root cap B. inside root hairs C. on top of the root cap D. under the cortex

One type of electromagnetic radiation that could harm humans

A 25.0-milliliter sample of HNO3 (aq) is neutralized by 32.1 milliliters of 0.150 M KOH (aq). What is the molarity of the HNO3 (aq) ? (1) 0.117 M (3) 0.193 M (2) 0.150 M (4) 0.300 M

Why are numbers in chemistry expressed in scientific notation?

Describe two human actions that cause water pollution.

The first-order decomposition of n2o at 1000 k has a rate constant of 0.76 s-1. if the initial concentration of n2o is 10.9 m, what is the concentration of n2o after 9.6 s

When a catalyst lowers the activation energy of a reaction the rate of the reaction?

Liquids: A) must be contained to stay in one spot B) have a variable volume, but a fixed mass C) are usually more dense than solids and gases D) cannot be changed into gases

Given the following list from the activity series of metals (from most active to least active) K, Na, Al, Mn, Cr, Cd, Co, Pb, Hg which reaction would you NOT expect to occur? 1. Co²⁺ (aq) + Al (s) → Al³⁺ (aq) + Co (s) 2.

Chemical reactions that release energy A. will not occur. B. need catalysts to occur. C. will always explode. D. often occur spontaneously.