Suppose you have 100 grams of a radioisotope with a half-life of 100 years. How much of the isotope will you have after 200 years?

How is heat transferred through radiation? A. Heat is transferred by energy waves moving through space. B. Heat is transferred by the movement of a liquid or gas. C. Heat is transferred by one molecule touching another. D.

An archaeologist finds a 1.62kg goblet that she believes to be made of pure gold. She determines that the volume of the goblet is 205mL. Calculate the density of the goblet

Which of these reactions are redox reactions? Check all that apply. Cd + HCl → CdCl2 + H2 CuCl2 + Na2S → 2NaCl + CuS CaCO3 → CaO + CO2 2ZnS + 3O2 → 2ZnO + 2SO2 CH4 + 2O2 → CO2 + 2H2O

Which is true about H3PO4 and NH3? A. Both are electrolytes, one is an Arrhenius acid and one is an Arrhenius base B. Both are electrolytes, only one is an Arrhenius acid or an Arrhenius base C.

An 8.5 g ice cube is placed into 255g of water. Calculate the temperature change of water when the ice melts

Why is photosynthesis so important to plants, and can't animals use it?

One way the government of Kim Jong-il controls the lives of the people who live in North Korea is by a. requiring every citizen to vote. b. controlling information its people receive from the outside world. c. enforcing free trade with other nations.

Give reasons 1) copper utensils and sheets become blackish after some days

Predict the spontaneity of a reaction (and the temperature dependence of the spontaneity) for each possible combination of signs for? H and? S (for the system).

At 29°C, Kp = 5.3 ✕ 102 atm-2 for the following reaction. N2 (g) + 3 H2 (g) equilibrium reaction arrow 2 NH3 (g) When a certain partial pressure of NH3 (g) is put into an otherwise empty rigid vessel at 29°C, equilibrium is reached when 55.