1. What are POLYATOMIC IONS?

2. What are POLYATOMIC IONS?
Lets first review what a monatomic ion is
What is a group of atoms with charge?
back to
naming
compounds

3. In a single atom (monatomic), charge results
from having either more electrons
or less electrons than protons.
More electrons than protons
= negative charge (anions) + +
Less electrons than protons
= positive charge (cations)

4. Mg 2+
Example: The magnesium ion has
two
less electrons than protons

5. 2+ two less electrons than protons Mg Example: The magnesium ion has
back to
polyatomic
ions
Example: The magnesium ion has
two
less electrons than protons

6. N O

7. two or more atoms covalently bonded together.
In a polyatomic ion,
two or more atoms covalently bonded together. N O

8. 1– N O
Together, they carry a charge

9. 1– The nitrate ion (NO3–) has, in total, one more electron
than protons

10. Mg(NO3)2 When balancing charges in an ionic compound,
the polyatomic ion acts as a single unit of charge: N O 1- N O 1- Mg 2+
Mg(NO3)2

11. 1- 1- 2+ N O N O Mg
Mg(NO3)2 2+

12. 1-
the charges are balanced 1- 2+ N O N O Mg
Mg(NO3)2 2+ 2-

13. back to
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back to
naming
compounds
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