Answer: Option (C) is the correct answer.
Explanation:
An ion is defined as a specie which is formed when a neutral atoms tends to gain or lose an electron.
When a neutral atom gain an electron then it forms a negative ion whereas when a neutral atom tends to lose an electron then it forms a positive ion.
For example, a neutral fluorine atom on gaining an electron will form 
ion. And, a sodium atom on losing an electron forms 
ion.
When a group of atoms form ions then it tends to form polyatomic ions.
Thus, we can conclude that group of atoms that gains or loses electrons is called a polyatomic ion.
Answer:
mass and distance
Explanation:
The strength of this force depends on the <u>mass</u>
of each object and
the <u>distance</u>
between them.
Answer:
2Mg + O₂ ⟶ 2MgO
Explanation:
Step 1. Start with the most complicated-looking formula (O₂?).
Put a 1 in front of it.
Mg + 1O₂ ⟶ MgO
Step 2. Balance O.
We have fixed 2 O on the left. We need 2O on the right. Put a 2 in front of MgO.
Mg + 1O₂ ⟶ 2MgO
Step 3. Balance Mg.
We have fixed 2 Mg on the right-hand side. We need 2 Mg atoms on the left. Put a 2 in front of Mg.
2Mg + 1O₂ ⟶ 2MgO
Every formula now has a coefficient. The equation should be balanced. Let’s check.
<u>Atom</u> <u>On the left</u> <u>On the righ</u>t
Mg 2 2
O 2 2
All atoms are balanced.
The balanced equation is
2Mg + O₂ ⟶ 2MgO
C6H12O6 +6O2 —> 6CO2 + 6H2O
Answer: The periodic table
Explanation: Demetri Mendeleyev is famous for developing the periodic table. He introduced it in 1869.
