Answer:
The molarity of the solution is 245, 2M.
Explanation:
We calculate the molarity, which is a concentration measure that indicates the moles of solute (in this case KCl03) in 1000ml of solution (1 liter):
0,25 L solution----- 61,3 moles of KCl03
1 L solution----x= (1 L solution x 61,3 moles of KCl03)/0,25 L solution
x=245, 2 moles of KCl03 --> <em>The molarity of the solution is 245, 2M</em>
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The specific heat capacity of this chunk of metal is equal to 0.32 J/g°C.
<u>Given the following data:</u>
- Quantity of energy = 400 Joules
- Initial temperature = 20°C
To determine the specific heat capacity of this chunk of metal:
<h3>
The formula for quantity of heat.</h3>
Mathematically, quantity of heat is given by the formula;

<u>Where:</u>
- Q represents the quantity of heat.
- m represents the mass of an object.
- c represents the specific heat capacity.
- ∅ represents the change in temperature.
Making c the subject of formula, we have:

Substituting the given parameters into the formula, we have;

Specific heat, c = 0.32 J/g°C.
Read more on specific heat here: brainly.com/question/2834175
0.004382166 Make sure to round to the right amount of Sig Figs
Answer:
Option B is correct.
4
Explanation:
We know that an atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example, if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.