which scientist proposed a modification to the theory of atomic number that esablished electron energy levels or shells

Describe Bohr's contribution to the atomic model. Enter your answer in the space provided.

How many unpaired electrons does oxygen have?

What is the mass number most similar to? The average mass of all isotopes of the element The sum of the atomic numbers of all isotopes The sum of the Masses of all the isotopes The average charge of all ions of the element

Which of the following compounds are held together by ionic bonds? Water, salt, sugar, carbon dioxide

How do the properties of elements change as you move across a period

How can hypothesis best be tested

Write a balanced equation for the combustion of 1 mol of C4H10O (l). Express your answer as a chemical equation. Identify all of the phases in your answer.

A thermonuclear chain reaction is considered to be a: -sustaining reaction in which the products cause new reactions fusion reaction because new material is combined many times }common phenomenon for all unstable uranium atoms proton creation

Which atoms are most likely to form covalent bonds?

Which phrase is the best description of weathering? A-Compacting Rocks B-Cementing Rocks Together C-Crystallizing to form minerals D-Breaking Rocks into fragments by physical or chemical means