Most elements on the periodic table are a) gases b) metals c) nonmetals d) rare earth elements ~~ (use graph) the periodic table organizes elements according to increasing a) atomic mass. b) energy level. c) atomic number. d) valence number. ~~ elements are pure substances. they are organized in the periodic able. each element has a unique atomic structure and chemical symbol. the chemical symbol is either one or two letters, the first letter of which is capitalized. can you identify the elements? check all the symbols that represents single element. co ca fe h2o si ne

Explanation:

1.   In a periodic table, there are alkali metals, alkaline earth metals, transition metals, non-metals and noble gases. Also, lanthanides and actinides present in the periodic table are radioactive in nature.

Therefore, MOST elements on the periodic table are metals.

2.   Number of protons present in an atom represents the atomic number. On the other hand, sum of number of protons and neutrons represent atomic mass of an atom.

When we move from left to right in a periodic table then there will be increase in number of both protons and neutrons. Hence, the periodic table organizes elements according to INCREASING atomic mass.

3.   An atom which contains atoms of only one substance is known as an element.

For example, Ca, Fe, Si and Ne are all elements.

Whereas a substance that contains atoms of two different elements with similar composition is known as a substance.

For example, CO, are compounds.

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