<u>Oxygen</u> is the most abundant element in the Earth's atmosphere.
The <u>valence</u> electrons are those found in the outermost energy level of an atom.
In the modern periodic table, elements are arranged in order of increasing atomic numbers. <u>True</u>
Elements can be classified as metals, nonmetals or metalloids. <u>True</u>
Nonmetals are good conductors of heat and electricity. <u>False</u>
Luster is a chemical property of metals. <u>True</u>
Halogens include fluorine, chlorine, bromine, iodine, and astatine. <u>True</u>
<h3>What is an element?</h3>
An element is a substance which cannot be split into simpler units by a ordinary chemical process
So therefore, Oxygen is the most abundant element in the Earth's atmosphere.
- The valence electrons are those found in the outermost energy level of an atom.
- In the modern periodic table, elements are arranged in order of their increasing atomic numbers True
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