Helium consists of two protons, two neutrons and two electrons, and has the chemical symbol He. Like hydrogen, it is a colorless and odorless gas. However, it is an unreactive element, and the lightest of the group called the "noble gases." It therefore doesn't play a role in biology...
The element that has the capacity to share four electrons in order to create four stable bonds with a variety of elements is one that is essential to all life in the universe. It is this unique characteristic that makes it an essential criterion for l...
What is the name of the He element? Predict which one is more stable (i.e., has the larger dissociation energy) and explain your answer. a. F_2 or F_2^+ b. NO or NO^+ c. CO or O_2 d. Li_2 or Be_2 Name the four common halogens and tell the normal phase of each. Wh...
This is because iron is an extremely stable element and stars aren't massive enough to trigger its fusion. When all nuclear fusion ceases, the star undergoes a final and catastrophic gravitational collapse. This triggers a supernova that flings the elements the star has forged during its life...
Protons supply the positive charge, and each element has a different number of them. The number of protons in the nucleus determines the atomic number of an element. It's different from atomic mass or atomic weight, which take into account the presence of neutrons. Every atom of a given ...
To complicate things a bit more, we sometimes find atoms of a chemical element that are a bit different to what we expect. Take carbon, for example. The ordinary carbon we find in the world around us is sometimes called carbon-12. It has six protons, six electrons, and six neutrons, ...
‘element’ as one informed by both definitions. She says that in Lavoisier’s time there was no option but to go for the analytical definition, because we understood next to nothing about what distinguishes elements at the fundamental level. Gradually the balance has tipped more towards a ‘...
element vs. compound Anelementis a substance that cannot be separated into simpler substances by chemical means. An element consists of anatomwith a unique combination ofprotons,neutrons, andelectrons. For example, the element hydrogen has one proton, one neutron, and one electron. We cannot use...
Element Any of the terms in the rectangular array of terms that constitute a matrix or determinant. Essence An extract that has the fundamental properties of a substance in concentrated form. Element Chemistry & Physics A substance composed of atoms having an identical number of protons in each ...
Medical radioisotopes such as iodine also lie outside what is known as the band of stability, but, in this case, they offer beneficial characteristics. Iodine-131 has four extra neutrons than its stable counterpart, and has a half-life of eight days. Since iodine can be safely ingested, it...