Which of the following statements about transition metals is true?
a.
they are never found uncombined in nature.
b.
they include familiar metals such as gold, silver, copper, and nickel.
c.
they are so soft that they can be cut with an ordinary knife.
d.
they are the most reactive of all the types of metals.

In a laboratory determination of the atomic weight of tin, a sample of tin is weighed in a crucible. nitric acid is added, and the reaction proceeds to give a hydrated tin(iv)oxide plus no2and h2o. the hydrated tin(iv)oxide is then heated strongly and reacts as follows: sno2.xh2o(s)sno2(s)+ xh2o(g)the sno2is finally cooled and weighed in the crucible. explain the effect on the calculated atomic weight of tin that would result from each of the following experimental errors: (a)considerable spattering occurs when the nitric acid is added to the tin.(b)the hydrated tin(iv)oxide is not heated sufficiently to change it completely to tin oxide.