<u>Answer:</u> The mass percent of lead in lead (IV) carbonate is 63.32 %
<u>Explanation:</u>
The given chemical formula of lead (IV) carbonate is 
To calculate the mass percentage of lead in lead (IV) carbonate, we use the equation:

Mass of lead = (1 × 207.2) = 207.2 g
Mass of lead (IV) carbonate = [(1 × 207.2) + (2 × 12) + (6 × 16)] = 327.2 g
Putting values in above equation, we get:

Hence, the mass percent of lead in lead (IV) carbonate is 63.32 %
I think the correct answer is option 3. CaCl2 is the compound that is an electrolyte when dissolved in water. An electrolyte is a substance that conducts electricity in solution. Calcium Chloride when in solution dissociates into ions which allows the flow of current in the solution.
<span>Oil and water don't mix because oil is made up of non-polar molecules while water molecules are polar in nature. Because water molecules are electrically charged, they get attracted to otherwater molecules and exclude the oil molecules. (this is from wiki)</span>
Answer:
The process where substance react with oxygen is called combustion.
Explanation:
When substance react with oxygen combustion is occur. The substance which burned is called fuel and in this process large amount of heat is released to the surrounding. It is exothermic process.
For example:
4Li + O₂ → 2Li₂O
2Mg + O₂ → 2MgO
S + O₂ → SO₂
The product which is formed as a result of combustion reaction are called oxides.
In given examples we can see that lithium, magnesium and sulfur react with oxygen and product formed is oxides of respective elements such as lithium oxide ( Li₂O), magnesium oxide (MgO) and sulfur oxide ( SO₂ ).
Answer:
Decreased
Explanation:
You're faster when you go downhill than you are uphill.