Biology

2. a negatively charged ion.
3. energy the energy possessed by a body by virtue of its position relative to others, stresses within itself, electric charge, and other factors.
5. an atom or molecule with a net electric charge due to the loss or gain of one or more electrons.
8. bond a weak type of bond that forms between a hydrogen atom and an electronegative atom in another molecule.
11. a measure of the tendency of an atom to attract a bonding pair of electrons.
13. a unit of mass used for expressing atomic and molecular weights.
15. bond a type of chemical bond that involves the electrostatic attraction between oppositely charged ions.
17. a state in which opposing forces or influences are balanced
18. elements chemical elements present in tiny amounts in a given environment or organism.
19. the combining power of an element, especially as measured by the number of hydrogen atoms it can displace or combine with.

1. bond a chemical bond that involves the sharing of electron pairs between atoms.
4. a substance consisting of atoms which all have the same number of protons.
6. a region in an atom where there is a high probability of finding electrons.
7. covalent a type of covalent bond where electrons are shared unequally between atoms, resulting in a partial positive and partial negative charge.
9. covalent a type of covalent bond where electrons are shared equally between atoms.
10. number the total number of protons and neutrons in an atomic nucleus.
12. variants of a particular chemical element which differ in neutron number.
14. mass the mass of an atom of a chemical element expressed in atomic mass units.
16. a positively charged ion.
20. a substance formed when two or more chemical elements are chemically bonded together.