Which of the following elements is only made in laboratories?

sb

cm

te

tb

A compound contains 46.7% nitrogen and 53.3% oxygen by mass. What is the empirical formula of the compound?

Electrical energy is used to spin the blades of a ceiling fan. If the electricity is cut off, the fan blades will slow down and eventually stop spinning. Why? A. All the kinetic energy of the fan blades has been transformed into potential energy. B.

A. Define the terms 'oxidation' and 'reduction. B. The oxidation number of S inS2O32 - is: C. The oxidation number of S inS4O62 - is: How were the assignations made?

If δh°rxn and δs°rxn are both positive values, what drives the spontaneous (favored) reaction and in what direction at standard conditions?

A chemist carefully measures the amount of heat needed to raise the temperature of a 278.0g sample of C5H12S from 0.8degree celsius to 15.9 degree celsius. The experiment shows that 8.46X10^3J of heat are needed.

A solution is made by dissolving 25.20 g of aluminum acetate in 185.0 mL of water. What is the concentration of acetate ions?

Which best describes how sediment forms? erosion breaks down rock and other material molten rock cools above earths surface loose material is cemented by pressure chemical changes cause sediment to compact together

How will you know whether a solution is saturated or supersaturated?

What is the number of moles of 27.6g of lithium?

Air is transferred from a 75 L tank where the pressure is 125 psi and the temperture is 288 k to a tire with a volume of 6.1 L and a pressure of 25 psi. What is the new temperture.