What does the “188” represent in Tantalum-188 A. mass number
B. atomic number
C. mass defect

mass number

Explanation:

When there is an element name followed by a dash and then a number, the number simply represents the mass number.

for example:

Oxygen- 18

18 represents the mass number of this particular isotope

the number of protons in the nucleus of a given element. has slight luster and conducts electricity at high temperatures like metal.but like a nonmetal,boron is brittle and does not conduct electricity well at low temperatures. in graphite, carbon is a soft,brittle solid.it is reflective,ductile,or malleable.