With evolution as the core theme of biology, we can explain traits shared by organisms as evidence of and traits that differ among organisms as evidence of

oak trees? ? what was listed

ionic bonds are two oppositely charged ions that attract. a sodium ion has a 1 positive charge; a chloride ion has a 1 negative charge. sodium and chloride have oppostive charged ions that attract which forms an ionic bond. a chemical bond formed when two atoms share electrons is called