How many elements exist naturally on earth?

How many atoms are in 1.75 mol CHCl3

Which of the following equations can be used to determine the change in enthalpy of a system? ΔHreaction=ΔHproducts*ΔHreactants ΔHreaction=ΔHproducts:ΔHreactants ΔHreaction=ΔHproducts+ΔHreactants ΔHreaction=ΔHproducts-ΔHreactants

Which of the following is not indicative of chemical change? a. Fizzing b. bubbling c. warming d. unexpected color change e. dissolving

4Al (s) + 3O2 (g) __> 2Al2O3 (s)

Explain whether the following statement is true or false -Considering only the most common isotope of each element, there is only one element that has more protons than neutron a true b false if true what element?

What is the [H3O+] of a solution with a pH of 2.56? 2.56 M, 2.75 x 10-3 M, 363 M, or - 0.408 M

What is the law of conservation of energy? A) energy can only be destroyed B) energy will always be renewed. C) energy cannot be created of destroyed. D) energy can never change forms.

Most metals are solid at room temperature, malleable, ductile, good conductors of heat and electricity, and react in acids to produce hydrogen gas. which of the properties mentioned is a chemical property? a. are malleable b. reacts with acids c.

Silver tarnishes when it comes into contact with hydrogen sulfide in the air. physical property or chemical property

When a volcanic irruption adds new rock to existing land and forms new islands is it considered destructive?