Explanation:
Just a few things to remember:
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# of neutrons = Mass number - # protons
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Mass number = # protons + # neutrons
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Atomic Number = # of protons
- # of electrons = # of protons - charge on the atom
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Symbol - use the atomic number to find the element in the periodic table
The answer is Na⁺.
Na⁺ is a positive ion of sodium that is due by the loss of one electron.
4He represents four atoms of helium. It is an idel gas, that do not form elementary molecules and exist in atom form.
Ca represent one atom of calcium and Mg one atom of magnesium. They are metals and do not form elementary molecules.
You can tell that a crystal is a crystal if it creates a rainbow prism effect. Or you can tell by tapping the crystal. If he crystal makes a musical ring noise (like how a glass cup would sound) it’s a crystal.
