20. Which of the following is NOT true for the atoms 13N, 14N, and 'N?

a. They all have the same mass number.

b. They are isotopes.

c. They all have the same atomic number.

d. They all have 7 protons.

e. They all have 7 electrons.

Balance the equation for the formation of ammonia from hydrogen gas and nitrogen gas using a set of the lowest possible integer coefficients. what is the coefficient in front of ammonia, nh3, in the balanced equation? n2 (g) + h2 (g) → nh3 (g)

What do the digestive and excretory systems have in common? Both break down food. Both produce urine. Both get rid of waste material. Both filter out waste material.

Two major organic products are formed in the reaction of p-chlorotoluene with sodium amide. draw the structure of both products.

Disease causing bacteria need oxygen to survive. true or false

Topographic map are a type of road map? True or false

Luis set a glass of ice water out side is the sunshine. when he looked at the glass 10 minutes later, the contents had changed. what kind of change happened to the ice water? A. evaperation B. conduction C. chemical change d. sudden change

A substance is considered to have a smaller surface area when ... A. it is a fine powder B. it is in large chunks C. you have a small amount of the substance D. you have a large amount of E. the substance

Which is the noble gas notation for chlorine? A-[Ne] 4s2 4p5 B-[Ne] 3s2 3p5 C-[Ne] 3s2 3p3 D-[Ne] 3p2 3p5

Is argon long hand or noble gas

Lithium, beryllium, and boron are elements with atomic number 3, 4, and 5, respectively. Even though they are three of the five simplest elements, why are they rare compared to many heavier elements?