As depth increases, the density of the layers decreases.
1. Na3PO4+Mg(NO3)2= NaNO3 + MgPO4
So this is not the answer.
2. Al+CuCl2= AlCl3+ Cu
So this is the answer.
3. Mg+O2= MgO2
So this is not an answer
4. Cl2+KI= KCl+I2
So this is also an answer
Hence B and C are answers
Answer is 56 protons and 56 electrons.
<em>Explanation;</em>
Atomic number is equal to number of protons. Hence, when the atomic number is 56, it means that atom has 56 protons.
When the element is in neutral state, number of protons = number of electrons. Hence, we can say that barium atom has 56 electrons.
But same element can have different number of neutrons. Those are called isotopes. Hence, we cannot say that there are 56 neutrons in barium atom without having its mass number. (Mass number = number of protons + number of neutrons)
Answer:
A whale bleeding from a cut.
Explanation:
Shivering in the cold, breathing hard during exercise, and sweating because it's hot are ways the body is working to maintain good functioning and to keep the body alive. Bleeding from a cut is not an example of this.
Ammonia undergoes combustion with oxygen to produce nitric oxide and water. The volume of the oxygen required to react with 720 ml of ammonia is 900 ml.
<h3>What is volume?</h3>
Volume is the area occupied by the substance and is the ratio of the mass to the density.
At STP, 1 mole of gas occupies 22.4 L of volume
Given,
Volume of ammonia reacted = 0.720 L
The combustion reaction is shown as,
From the stoichiometry of the reaction, it can be said that,
L of ammonia reacts with 
L of oxygen gas.
So, 0.720 L of ammonia will react with:
Therefore, the volume of oxygen required is 900 mL.
Learn more about volume here:
brainly.com/question/14090111
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