Which of the following rocks is formed by cooling lava?

obsidian

limestone

sandstone

marble

Scientific notation steps

White light, which consists of all frequencies, forms which type of spectrum?

How did the discoveries of scandium (Sc) and germanium (Ge) affect Mendeleev's work? A. They showed Mendeleev's table needed different groups. B. They showed Mendeleev's predictions were flawed. C. They showed Mendeleev's predictions were correct.

Select the correct formula for the polyatomic ion. The formula for ammonium carbonate: NH4HCO3 NH4CO3 (NH4) 2CO3

All of the following are indicators of chemical change except ... a. Change in color b. Production of a gas c. Formation of a precipitate d. All of the above are indicators of chemical change

A 0.239 gram sample of a gas in a 100-mL flask exerts a pressure of 603 mm Hg at 14 degrees Celsius. What is the gas?

Which of the following is true about a redox reaction? In a redox reaction, an electron is lost by the reducing agent. In a redox reaction an electron is lost by the oxidizing agent.

Is the equation above balanced? How do you know? Mg + 2HCl → MgCl2 + H2

What characteristics do atoms of carbon-12, carbon-13, and carbon-14 have in common?

Which of the following changes would decrease the rate at which a solid solute dissolves in a liquid solvent? A. Decreasing pressure B. Decreasing surface area C. Increasing rate of stirring D. Increasing temperature