Answer:
When two or more atoms chemically bond together, they form a molecule. Sometimes the atoms are all from the same element.
A Compound.
Explanation:
For example, when three oxygen atoms bond together, they form a molecule of ozone (O3). If a molecule forms from atoms of two or more different elements, we call it a compound.
Hope this helps!!
Answer:
Zn²⁺ gets reduced
Explanation:
An electrolytic cell runs in the opposite direction of a galvanic cell. Applying a current to the galvanic cell Zn | Zn²⁺ || Ni²⁺ | Ni would convert the Zn anode to a cathode and cause Zn²⁺ to be reduced.
C- K4O8 and K2O4
K4O8/4 =KO2
K2O4/2 =KO2
Answer : The mass of helium gas in the balloon is, 1.23 grams.
Explanation : Given,
Volume of helium gas = 6.9 L
First we have to calculate moles of helium gas at STP.
As we know that, 1 mole of substance occupy 22.4 L volume of gas.
As, 22.4 L volume of helium gas present in 1 mole of helium
So, 6.9 L volume of helium gas present in
of helium
Now we have to calculate the mass of helium gas.

Molar mass of He gas = 4 g/mol

Thus, the mass of helium gas in the balloon is, 1.23 grams.