When scientists measure the ratio between the radioactive parent isotope and the daughter products in a sample to be dated, this is (earth science)

An atom of nitrogen had seven protons in its nucleus. how many electrons does it have

The vaccine in a flu shot contains weakened flu viruses. how does a flu shot work with the immune system? a. it destroys lymphocytes. b. it destroys macrophages. c. it activates macrophages. d. it activates lymphocytes.

If the rna molecule in a human has the nucleotide sequence of guu, this would the amino acid valine would be needed to make the protein. how would this cha process was occurring in a mushroom?