In the Periodic Table of Elements, helium, a noble gas, is placed in Group 8A. Why?

In pea plants, the allele for tallness (t) is dominant to the allele for shortness (t). in the cross between a tall pea plant and a short pea plant shown below, what is the probability that the resulting offspring will be tall? whats the percent

An unknown substance is a white solid at room temperature and has a melting point of 78 °c. which of the following substances is most likely to be the identity of the unknown sample? a. naphthalene, a molecular solid with the formula c10h8 b. silica, a network solid held together by covalent bonds with the formula sio2 c. calcium chloride, an ionic compound with the formula cacl2 d. water, an molecular compound with the formula h2o

How much mass would a mole of hydrogen molecules contain? recall that hydrogen is diatomic. g/mol