Why is a match being struck a physical change

Universal indicator is an acid/base indicator that can be added to a solution to determine its pH. Universal indicator turns solutions different colors based on its pH.

If a solution contains 1 x 106 hb molecules, how many o2 binding sites are available? if the solution of hb is 50% saturated with o2, how many binding sites are occupied by o2?

Beware of this when swimming near shore

Why is the sunlight written above the arrow in the equation, rather than on either side of it?

A piece of paper burns in a closed flask. As it burns, does the number of atoms in the flask increase, decrease, or remain the same? A. The number and type of atoms increase. B. The number and type of atoms decrease. C.

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