Which of the following is a polyatomic ion?

A. Calcium, Ca2+

B. Carbide, C4-

C. Sulfate, SO4

D. Selenide, Se2-

Match the effects on the concentration of SO3 gas when the following changes occur after initial equilibrium has been established in this system (N. C. = no change). 2SO2 (g) + O2 (g) 2SO3 (g) + 46.

The enthalpy of formation of xef2 (g) is - 108 kj mol-1 and the bond dissociation enthalpy of the f-f bond is 155 kj mol-1. what is the average bond dissociation enthalpy of a xe-f bond

If the electronegativity difference between the elements in compound n a x is 2.1 what is element X a. Bromineb. chlorinec. fluorined. oxygen

The nuclear charge an electron actually experiences is called the ___ nuclear charge (Zeff). This charge is always ___ than the actual nuclear charge since in many-electron systems the electrons ___ each other from the nucleus.

Use chemistry in a sentence not love chemistry science chemistry

If you were traveling through space and landed on a different planet, how might your mass and weight compare to their values on Earth? Why?

Which principle explains why it is necessary to have safety belts in cars?

Hydrochloric acid is purchased in 12 molar concentrations. If I needed 200 ml of 2.0 molar HCl, how many milliliters of the concentrated solution would I need

Which of the following represents a chemical change? Bending a wire Freezing of water Fireworks exploding Melting of a wax candle

5.00 L of a gas is collected at 100K and then allowed to expand to 20.0 L. What must the new temperature be in order to maintain the same pressure? A. 400 °C B. 127 °C C. 223 °C D. 627°C