Which of the following is NOT a reversible reaction?

a cutting a tree into logs

b. Dissolving sugar into water

c. Melting chocolate

d Tying your shoes

How many moles of oxygen are in 1 mole of Ca (NO3) 2?

Which tool is used to detect yellow light rays emitted by stars from outer space? x-ray optical telescope gamma telescope optical telescope infrared telescope

What is pH? A. A component of solutions that makes them acidic B. A concentration of total ions dissolved in solution C. A measure indicated how acidic a solution is D. A level of dissolved gasses that are in aolution

True or false: the density of an object can be calculated by dividing its length by its width.

Which of the following statements about the particles in a solution is true? A When an ionic solid mixes with water, its ions repel water molecules. B When a molecular solid mixes with water, the covalent bonds are broken.

How to assign oxidation and reduction numbers

How to tell difference between hydrogen gas and oxygen gas?

Why do atoms have different speed

Jose gets up from his seat on the bus to move closer to the front. Just as he begins to walk forward, the bus stops at a light.

How would you present weight change if Earth had twice the mass that it does