When a chemical reaction takes in energy it might feel

A. Hot

B. Cold

C. Boiling

D. Electric

In order to withhold the specific chemical identity of a toxic substance, employers do not need to:

The Hrxn of formation of carbon dioxide is negative. Which statement is true? The reaction is endothermic. The reaction is exothermic. The amount of carbon dioxide is more than the amount of reactants.

What is the basic organizing feature of the periodic table of elements?

How do you determine if something is an atom or ion?

Which of the following is not a stimulus:hearing a loud noise, sneezing, touching a hot object, tasting a lemon?

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