Silicon dioxide powder dissolves in water. Is this a physical or a chemical change?

How many base units exist?

Which is a pure substance?

Since the number of atoms in a substance is so large, a unit to count them was created. This unit is the number of atoms in 12 grams of carbon-12 known as

A drug company is testing the effectiveness os a new blood pursur medicine using rats as the test subject. What are some possible factors that must stay current during the testing?

A chemical reaction is carried out in a closed container. The energy absorbed by the chemical reaction is 150 kJ. How much energy moves inward from the air or the walls of the container? A. 75 kJ B. 100 kJ C. 150 kJ D. 200 kJ

Which describes a force in an unstable nucleus? A. The strong nuclear force is greater than the electrostatic force. B. The electrostatic force is greater than the weak nuclear force. C.

1. How are Energy and Power related? 2. What are the two basic types of Energy? How are they similar? How are they different? 3. Describe the difference between Gravitational Potential Energy and Elastic Potential Energy?

At what temperature does water evaporate?

What happens to a stream when it is acidified?

Which energy changes are associated with a liquid freezing?