Which equation shows a conservation of mass?
(1) na + cl2 --> nacl
(2) al + br2 --> albr3
(3) h2o --> h + o2
(4) pcl5 --> pcl3 + cl2

How does a scientist the government? a. the scientist tells people in society what to do. b. the scientist determines the policies that the government spends money on. c. the scientist provides unbiased information to the government. d. the scientist makes laws based on his or her research results.

Awhite powder is added to a solution. the images show observations made before the powder is added, just after the powder has been added, and a little while later. (the liquid in the small beaker is phenol red solution.) what evidence shows that a chemical change has taken place?

4786 joules of heat are transferred to a 89.0 gramsample of an unknown material, with an initialtemperature of 23.0°c. what is the specific heat of thematerialif the final temperature is 89.5 °c?