How man kilo-calories of heat are required to raise the temperature of 225 g of aluminum from 20 C to 100 C?

0.59 kcal

3.8 kcal

38 kcal

85 kcal

Which type of bonding is present in a sample of an element that is malleable? (1) ionic (2) metallic (3) nonpolar covalent (4) polar covalent

Adenine (a) pairs with a: cytosine (c) B: Guanine (g) C: Thymine (T)

We create an electron with wavefunction ψ = [ψ1s (r) + 3ψ3s (r) ] / √ 10. Find the expected value hEi of the energy in that state. Use the energies of the hydrogen atom to extract your answer in electron volts.

Which of the following is not true about limiting and excess reagents? a. the amount of product obtained is determined by the limiting reagent. b. a balanced equation is necessary to determine which reactant is limiting reagent. c.

Isotopes and its uses

Assuming that air contains 78 percent N2, 21 percent O2 and 1 percent Ar, all by volume. How many molecules of each type of gas are present in 1.0 L of air at STP?

Two children are playing tag. Child A who is doing the chasing can run 100m in 24 seconds Child B is running away from child A and can run 64m in 21 seconds.

What ion does a base increase

What is the definition of Amplitude?

An excess of NiCO3, 12 g, was added to 40cm cube of sulpheric acid, 2.0 mol/dm cube. The unreacted nickel carbonate was filtered out and the filtrate evaporated to optain the crystals.