How many neutrons does an atom of al-27 have? (hint: look at the periodic table for the atomic number aluminum (al) 13 14 27 40 aluminum has the atomic number of 13?

Identify the mixture of gasoline and motor oil and suggest a technique for separating their components. 1. homogeneous; decanting 2. heterogeneous; decanting 3. heterogeneous; distillation 4. homogeneous; distillation 5.

What scientist was responsible for discovering the neutron?

A student is given four solid samples labeled W, X, Y, and Z. All have a metallic luster. She is told that the solids could be gold, lead sulfide, mica (which is quartz, or SiO2), and iodine.

Anions have more ___ then __ A) protons, neutrons B) neutrons, protons C) protons, electrons D) electrons, protons

What holds atoms together in a chemical bond?

The volume of 1 mole of o2 gas at T=273k P=1atm is? A 6.02 x 10^-23 ml B 760 L C 22.4 L D 2.24 L E 224 L

There are two stable isotopes of bromine. Their masses are 78.9183 and 80.9163 amu. If the average atomic mass of bromine is 79.9091 amu, what is the natural abundance of the heavier isotope? percent abundance of 81Br __%

If 1.00 mol of argon is placed in a 0.500-L container at 20.0 ∘C, what is the difference between the ideal pressure (as predicted by the ideal gas law) and the real pressure (as predicted by the van der Waals equation) ? For argon, a=1.

Which of these is a covalent compound? 1. AICI3 2. CO 3. MgO 4. LiCI

What is a protein used for