How are elements arranged in the periodic table? a. by their properties b. alphabetically c. by how much they are worth d. in the order they were discovered 2. (10 pt) which is the correct symbol for the element silicon? a. si b. s c. si d. sil 3. (10 pt) all atoms of an element are . a. flammable b. visible under a microscope c. alike d. different 4. (10 pt) elements that are usually shiny and good conductors of heat and electricity are known as a. gases b. metals c. solids d. nonmetals 5. (10 pt) the most recent model of an atom is the a. bohr model b. einstein model c. nucleus model d. electron cloud model 6. (10 pt) elements that are usually dull, brittle, and do not conduct electricity are known as a. gases b. metals c. solids d. nonmetals 7. (10 pt) elements join together to form a. compounds b. ions c. protons d. atomic masses 8. (10 pt) which picture best shows an atom? a. b. c. d. 9. (10 pt) in order for a chemical reaction to take place, a certain amount of must be present. a. heat b. friction c. chemicals d. energy 10. (10 pt) enzymes are in the body that speed up chemical reactions. a. catalysts b. cells c. concentrations d. chloroplasts