look at the two question marks between zinc (zn) and arsenic (as). at the time, no elements were known with atomic weights between 65.2 and 75. but mendeleev predicted that two elements must exist with atomic weights in this range.
what led mendeleev to predict that two undiscovered elements existed in that range?

Theoretical temperature at which molecules stop moving and no more heat can be removed from the object. kelvin: absolute zero degrees. none of the above.

Answerd. may include all of these are many definitions of bases: the  brønsted-lowry definition of acids and bases says that bases are proton acceptors.the arrhenius definition of acids and bases says that bases increase [oh⁻] in solution (thereby producing oh⁻ ions)the lewis definition of acids and bases says that bases donate electron pairs.therefore, the sensible answer is that a base may include all of the described characteristics.

B. nuclear reactions could first occur.