Which of the following is NOT one of the base pairs of DNA?

a. guanine

b. cytosine

c. thymine

d. adrenaline

How many significant figures are represented in each of the following numbers? a) 7.1 x 10^-5 b) 0.00677 c) 750

The air in a balloon is heated up. Give two effects this has on the air particles.

Impure crystalline (solid) substances can be purified by recrystallization from a suitable solvent. Arrange the steps of the recrystallization procedure, from start to finish. Weigh the crystals into a tared flask.

What is the density of an object if it's mass is 15 g and it's volume is 3cm3

Element Name Symbol Mass Number Atomic Number Number of Protons Number of Neutrons Number of Electrons Lithium Carbon Chlorine Silver Lead Calcium Tantalum Radium Samarium Uranium Americium Lawrencium

Extend E1 Explain why the arrangement, movement and energy of particles change during changes of state.

What is in a banana? give me specifics?!

Addition of an excess of lead (II) nitrate to a 50.0mL solution of magnesium chloride caused a formation of 7.35g of lead (II) chloride precipitate. What was the molar concentration of chloride ions in the solution (in mol/L) ?

2.70 L of a gas has a pressure of 0.63 atm. What is the volume of the gas at 105 kPa?

Which statements describe Rutherford's model of the atom? Select all that apply.