What is one of the signs that a change is a chemical change? A. A solution is formed.
B. A new shape is taken.
C. Light is produced. D. A solid melts.
please help

The difference between the atomic number of an element and the element’s atomic mass is the number of ions.

6. using 3 – 4 sentences explain (in your own words) why water expands when it freezes? 7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation.

What mass of natural gas (ch4) must you burn to emit 276 kj of heat?