Why do solids have a fixed shape?
a. the particles vibrate
b. the particles are free flowing
c. the particles do not move
d. the particles are tightly packed together

Which is true of chemicals? a. things containing chemicals always cost a lot of money. b. chemicals are never dangerous. c. chemicals are in many substances in a home. d. chemicals are rarely found on earth.

Calculate the number of moles of ethane in 100 grams

Classify this reaction: 2al+n2-> aln.