Which contribution to the body of scientific knowledge is most recent?

a) the development of the lever

b) the confirmation of the double-helix structure of DNA

c) the discovery of electricity

d) the theory of evolution

Balance the equation NH4OH + HCl + H2O = NH3 + Cl2 + H2 + H2O

What would happen to life if earth were in a different location within the solar system

If an element, X, can form an oxide that has theformula X2O3, then element X would most likely be located on the Periodic Table in the same group as (1) Ba (3) In (2) Cd (4) Na

Why do nonmetals tend to gain electrons to form negative ions?

Which of the following is not true regarding an acid? a. can donate a proton (H+) to some other substance b. can accept a proton (H+) from some other substance c. releases hydrogen ions (H+) when dissolved in water d.

A container has a volume of 200 L at 0.94 atm and 25 C. The pressure changes to 1.00 atm and the temperature changes to 0 C. What is the new volume of the container

f litmus paper is dipped in an acidic solution and then in a basic one, what will happen? The paper will turn from blue to red. The paper will turn from red to clear. The paper will turn from blue to clear. The solution will turn from red to blue.

You need to make an aqueous solution of 0.125 M barium chloride for an experiment in lab, using a 250 mL volumetric flask. How much solid barium chloride should you add?

Relative to the sum of the masses of its constituent nucleons, the mass of a nucleus is: greater the same smaller sometimes greater and sometimes smaller

Smallpox epidemic among Native Americans?