When an excited electron in an atom moves to the ground state, the electron ...

Where are electrons, protons and neutrons located? (inside/outside the neucleus

Which statement contrasts the two types of mixtures? A. A heterogeneous mixture has a uniform composition, whereas a homogeneous mixture has visually distinguishable parts. B.

A food substance kept at 0°c becomes rotten in 8.3 days. the same food rots in 10.6 hours at 30°c. assuming the kinetics of the microorganisms enzymatic action is responsible for the rate of decay, what is the activation energy for the decomposition

The barium isotope 133ba has a half-life of 10.5 years. a sample begins with 1.1*1010 133ba atoms. how many are left after (a) 5 years, (b) 30 years, and (c) 190 years?

What is solubility in chemistry?

C₂H₂ + O2 - CO₂ + H₂ How many moles of oxygen are necessary to react completely with 4.0 moles of propane (CH) ?

What are the two main classifications of energy resources?

A liquid is heated and a solid forms at the bottom of the beaker. Is this a physical or chemical change?

How to predict the formula of an ionic compound based on the charges of the ions?

Which of the following kingdoms in one-celled organisms