Why are the atomic masses for most elements not whole numbers?

What is the mole ratio of NO2 to O2

Which is a correct comparison between the modern quantum model and John Dalton's model of the atom? a. The modern model is not as widely accepted by scientists as Dalton's model. b.

What is the weight in grams of 1 mole of ammonium sulfate (NH4) 2SO4?

An element has three naturally occurring isotopes. The relative abundances of the isotopes are 0.27%, 9.25%, and 90.48%. The most abundant isotope has an atomic mass of 19.99 amu. The least abundant isotope has an atomic mass of 20.

Convert 2.5 miles to km

Neon is a gas made up of one type of atom. Which term best describes neon? A) molecule B) element C) compound D) mixture

When the liquid is poured through a fliter,

A student went to the dentist and found out that he had a cavity. He always brushes his teeth twice a day, so he didn't understand how he got a cavity.

A force of 8,480 n is applied to a cart to accelerate it at a rate of 26.5 m/s2. what is the mass of the cart? 865 kg 320 kg 12.1 kg 3.12 kg

Within a group, which period, top or bottom is likely to contain atoms with the larger radius?