Match these items. 1. symbol for copper Cu 2. smallest unit retaining properties of element element 3. C 6H is an example of an mixture 4. symbol for hydrogen organic compound 5. symbol for sulfur atom 6. a primary substance that cannot be divided into separate substances 7. NaCl is an example of an S 8. a physical combination of two or more pure substances compound 9. any chemical combination of elements Fe 10. symbol for iron inorganic compound

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.

Calculate the frequency of a wave in a spring toy. the wave has a speed of 1.1 meters per second and a wavelength of 0.1 meters. *

What is the chemical formula for dihydrogen monoxide