Intro to Chemistry

5. A change of one substance to another.
8. Particles in the nucleus with an electric charge of 1+
10. Any characteristic of a material that you can observe without changing the identity of the substance.
11. Table where elements are arranged by increasing atomic number, and periodic changes in physical and chemical properties.
16. The vertical columns in the periodic table.
17. The process of separating substances, such as salt and water, in a mixture by evaporating a liquid and recondensing its vapor.
19. Any characteristic of a material that you can observe that produces one or more new substances.
20. The sum of the number of protons and the number of neutrons in the nucleus of an atom.

1. The mass of all substances that are present before a chemical change, known as the reactants, equals the mass of all of the substances that remains after the change, which are called the products.
2. Uses the chemical symbol of an element surrounded by dots to represent the number of electrons in the outermost energy level.
3. The number of protons in an atoms's nucleus.
4. The horizontal rows of elements in the periodic table.
6. An element is matter that is composed of only one type of atom.
7. Particles with an electric charge of 1-
9. A change in size, shape, or state of matter in which the identity of the substance remains the same.
12. The small, positively charge center of he atom.
13. Atoms of the same element that have different numbers of neutrons.
14. Smaller particles that make up protons and neutrons.
15. The area around the nucleus of an atom where electrons are most likely to be found.
18. The weighted average mass of all naturally occurring isotopes of an element, measured in atomic mass units, according to their natural abundances.