A radioactive element is half disintegrated in 40 minutes. What is the time required for the decay of 75% of the element

Other than rain what kinds of precipitation are there?

Which of these statements correctly describes covalent bonds? A) Covalent bonds are formed between a metal and a nonmetal. B) The formation of covalent bonds involves the sharing of electrons.

a gas cylinder contains 2.0 mol of gas X and 6.0 mol of gas Y at a total pressute of 2.1 atm. what is he partial pressure of gas Y?

What mass of H2SO4 is contained in 60.00 mL of a 5.85 M solution of sulfuric acid

Which of the following aqueous solutions are good buffer systems? . 0.11 M sodium hydroxide + 0.30 M sodium bromide 0.33 M potassium chloride + 0.20 M calcium chloride 0.28 M nitric acid + 0.23 M sodium nitrate 0.31 M ammonia + 0.

What is the total pressure when 0.400 g of H2, 2.00 g of N2, and 10.5 g of CO2 are injected into a 10.0 liter flask at 273 K?

The balanced chemical equation for the combustion of methane is: CH4 (g) + 2 O2 (g) → CO2 (g) + 2 H2O (g) Which of the following statements concerning this chemical equation is/are correct? 1.

In one kind of nuclear reaction, two nuclei fuse, or join together, to form a larger nucleus. This kind of reaction happens only at very high pressures. Explain why such high pressures are necessary to cause these reactions to occur.

Check the approach to obtain the correct conversion equation. Use the temperature in °F to find the temperature in °C. °C

What is the volume of a gas at 50.0 Celsius and. 80 atm if there are. 75 moles of a gas present?