What are the three primary required elements which plants obtain from soil?

oxygen

nitrogen

hydrogen

phosphorus

potassium

trace elements

Select the correct answer. Which of the following best describes half-life? A. half of the time it takes for the reaction to go to completion B. half of the initial rate of reaction for a given concentration C.

List the numbers of protons, neutrons, and electrons in Chlorine-18.

At constant temperature 10.0L of N, at 0.983 atm is compressed to 2.88L. What is the final pressure of N,? 0.283 atm b) 1.51 atm c) 3.41 atm d 29.3 atm a)

The following reaction is at equilibrium in a sealed container. N2 (g) + 3H2 (g) 2NH3 (g) delta Hrxn <0 Which will increase the value of Kc? A. Adding a catalyst B. Adding N2 C. Increasing pressure D. Lowering the temperature E. NOne of the above

What does the sign represent with respect to electrons? A. opposite spin of two electrons B. different principal energy levels of two electrons C. distances of two electrons from the nucleus D.

A hot meal plate at 150 has been placed in air at room temperature. Which event would most likely take place over the next few minutes

What is the molarity of solution that contains 5.80 grams of nickel nitrate, ni (no3) 2 in 500. ml?

Hydrogen has three isotopes with mass numbers of 1, 2, and 3 and has an average atomic mass of 1.00794 amu. This information indicates that 1. equal numbers of each isotope are present 2. more isotopes have an atomic mass of 2 or 3 than of 1 3.

Describe the process of how visible light is produced

Which of the following contains both ionic and covalent bonding? CH4 NaCl NH4Cl N2O4 If the formula for a compound is represented by X2Y3 and the charge on the Y ion is - 2, what is the charge in the X ion? +1 +2 +3 +4