Which of the following can be observed without changing the chemical makeup of a substance? A. hardness
B. toxicity
C. flammability
D. reactivity with oxygen

What is the molar mass of potassium nitrate, kno3

How many atoms or molecules are there in a mole of a substance?

Bridget is in science class. her teacher gives her two unknown substances and asks her to determine their relative ph. she places a piece of red litmus paper into both substances. the litmus paper turns purple when she places it into substance i. the litmus paper turns blue when she places it into substance ii. a. substance i is a neutral substance and substance ii is an acid. b. substance i is a neutral substance and substance ii is a base. c. substance i is an acid and substance ii is a base. d. substance i is a base and substance ii is a neutral substance.