How many lone pairs of electrons are on nitrogen in nf3?

What substances that are formed by the chemical combination of two or more elements in definite proportions

What is the focus of the bandwagon advertising style? to try to persuade someone to do something based on the fact that "everyone's doing it" to try to persuade someone to avoid doing something based on the fact that "it's unhealthy" to try to

Mineral oil can be used in place of mercury in manometers when small pressure changes are to be measured. What is the pressure of an oxygen sample in mm of mineral oil if its pressure is 28.5 mm Hg? (d of mineral oil = 0.88 g/mL; d of Hg = 13.

A stock bottle of an acid reads: 56% by mass and 1.25 specific gravity. If the molar mass of the acid is 70g, find the mole per cubic decimeter

A substance with a pH of 4.0?

Fumaric acid is an organic compound composed of 41.39%, 3.47%, and the rest oxygen. If 0.288 mol of fumaric acid has a mass of 33.4 g, what are the empirical and molecular fomulas of fumaric acid

What is an isotope? Give an example of an element with isotopes.

Consider the reaction between liquid water and aqueous magnesium nitride to form solid magnesium oxide and ammonia gas. If magnesium nitride is present in excess, how many moles of water are needed to form 9.17*1023 ammonia molecules?

The properties of elements are arranged by ... A. mass numbers B. atomic masses C. atomic radii D. atomic numbers

When a tire is inflated with air is it a chemical or physical change?