a) When the reaction takes place a yellow precipitate will be formed.
b) The law of conservation of mass is true.
<u>Explanation:</u>
a) When a lead nitrate solution is mixed with a potassium chromate solution, a yellow precipitate containing lead forms according to the equation:
→ 
b) Law of conservation of mass for the given reaction is true.
From the given table we know the mass of reactants and its products.
Law of conservation of mass is a principle when a reaction takes place in a closed system, the mass of the products and reactants in the system doesn't change.
⇒The sum of the mass of the reactants = The sum of the mass of the products.
The sum of the reactants = 128.71+128.97.
= 257.68 g.
The sum of the products = 154.10+103.58.
= 257.68 g.
Thus law of conservation of mass is true for the above reaction.
Answer : The technology that can make coal a cleaner fuel is to use lower quality of coal with high sulfur content.
Explanation : Using lower quality of coal with high amount of sulfur in it can make coal a cleaner fuel because of high amount of sulfur it will have better combustion.
I would say it is a chemical change because after a while, the nails start to rust. Now they only rust after about a week though. But rust is a chemical change.
has 37 electrons in the orbit about its nucleus.
<h3>How to write an atomic symbol with atomic mass and atomic number?</h3>
Atomic mass is the total number of neutrons and protons present in the nucleus of an element.
The atomic number is the total number of protons present in the nucleus of an element.
For writing an atomic symbol, atomic mass is written on the top left of the atomic symbol, and the atomic number is written on the downside of the left of the symbol.

An electrically neutral atom is an atom that has an equal number of electrons as well as protons.
Thus from the above conclusion we can say that
has 37 electrons.
Learn more about Atomic mass and atomic number here:
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