Answer:
Any substance that cannot be decomposed into simpler substances by ordinary chemical processes.
Another definition:
An element is the simplest pure substance which can neither be split nor built up from other simpler substances by chemical reaction
28) All elements are made of atoms
29)Protons and Neutrons
-Electrons make up the outside of the Nucleus
Answer: In metallic bonds, the mobile electrons surrounding the positive ions are called <u><em>dipole</em></u>.
The minimum energy required to excite a hydrogen atom from its lowest energy level is 10.2 eV.
<h3>What is excitation?</h3>
The term excitation has to do with the promotion of an electron from a lower to a higher energy level.
In this case, we are dealing with the hydrogen atom having only one electron. Thus, the minimum energy required to excite a hydrogen atom from its lowest energy level is 10.2 eV.
Learn more about energy level:brainly.com/question/17396431
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I believe it would weigh less if it’s blown up with helium because helium is lighter than air
