Solve for x (1/2)x + (1/3)x = 1

To eliminate the fractions, you need to find a common denominator. The smallest common denominator possible is 6. If you multiple both sides by 6, you will have 3x+2x = 6. Now you can add like terms to get 5x = 6. To get the variable by itself you would divide by 5 to get an answer of x = 6/5 or 1.2

What is the nucleus of an atom made up of and what is its charge? A. electrons and neutrons; negative charge B. electrons and protons; positive charge C. protons and neutrons; negative charge D. protons and neutrons; positive charge

The correct answer is D. The nucleus of an atom only contains protons and neutrons. Since protons have a positive charge, and neutrons do not have a charge, the nucleus has a positive charge.

What is the name for an atom that has different atomic mass but the same chemical properties?

An isotope is an atom that has two or more forms of the same element with equal number of protons but different number of neutrons. This means, the different forms have different atomic mass but they have the same chemical properties.