Element Chemistry Example 4

Follow the full solution, then compare it with the other examples linked below.

Example 4

medium
Sample A has atoms with 8 protons and 8 electrons. Sample B has atoms with 8 protons and 10 electrons. Are they the same element? Explain.

Solution

  1. 1
    An element is defined by its number of protons. Both samples have 8 protons, so both are oxygen.
  2. 2
    Sample B has extra electrons, so it is an oxygen ion, but it is still the same element because the proton count did not change.

Answer

Yes. Both are oxygen because both have 8 protons.
Element identity comes from proton number, not electron number. Changing electrons changes charge, but changing protons would create a different element.

About Element

A pure substance consisting entirely of atoms with the same number of protons (same atomic number), which cannot be broken down into simpler substances by.

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More Element Examples

Example 1 easy

Explain why gold (Au) and oxygen (O) are considered elements, while water ([formula]) is not.

Example 2 medium

Iron (Fe) has atomic number 26. How many protons and electrons does a neutral iron atom have? If iro

Example 3 easy

Classify each as an element or compound: (a) [formula], (b) [formula], (c) [formula], (d) [formula].

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