HARD
Earn 100

Which of the following best describes a chemical reaction based on physical contact?
(a)A reaction in which heat is released
(b)A reaction in which substances interact in close proximity
(c)A reaction that requires light to occur
(d)A reaction that involves only gas-phase substances

50% studentsanswered this correctly
Important Questions on Changes Around Us
HARD

HARD

HARD

HARD

HARD

MEDIUM

MEDIUM

MEDIUM

HARD

HARD

HARD

HARD

HARD

MEDIUM

HARD

HARD

EASY

EASY

HARD

HARD

