1 When barium chloride is allowed to react with silver nitrate to give barium nitrate and silver chloride, what are the coefficients for the balanced equation?

___BaCl2 (aq) + ___AgNO3 (aq) → ___AgCl (s) + ___Ba(NO3)2 (aq)
a)1, 2, 2, 1
b)1, 1, 1, 1
c)1, 2, 3, 1
d)1, 1, 1, 2

Which is true about metals used for jewelry, such as platinum and gold? a. they have low flammability. b. they have low reactivity. c. they have high flammability. d. they have high reactivity.

The velocity of any object depends upon a) the location of the object. b) the location of the observer. c) which measurement tools are used. d) the relative motion of the observer.

Why is it important for scientists to review and repeat the work of other scientists? 1.a scientific theory must be tested three times before it is proven. 2.the scientific method only applies to repeated experiments. 3.an experiment may have had errors that the scientists didn't recognize. 4.the results of individual scientists may be influenced by bias. 5.an experiment must be performed twice before the data can be analyzed.