<span>A physical change basically involves a change in physical properties. Some examples of physical properties include: texture, shape, size, color, volume, mass, weight, etc.
The water melting has changed the shape and therefore it's physical properties, but the chemical nature of the water has not been altered.
So that's why it's a physical change, and not a chemical change.</span>
Answer:
2
Explanation:
The atom shown in the image has 2 core electrons.
Electrons are the negatively charged particles within an atom. Therefore the total number of electrons surrounding the nucleus in the given specie is 7.
So;
We have 2 core electrons
And 5 valence electrons
The core electrons are the inner orbital electrons.
The valence electrons are the outermost electrons.
<u>Answer:</u> The force that must be applied is 15 N.
<u>Explanation:</u>
Force exerted on the object is defined as the product of mass of the object and the acceleration of the object.
Mathematically,
where,
F = force exerted = ?
m = mass of the object = 3 kg
a = acceleration of the object = 
Putting values in above equation, we get:
Hence, the force that must be applied is 15 N.
For 7A(17) :
Electronic configuration 
So, there are 5 unpaired electrons present in group 7A(17).
<h3>
What are Unpaired Electrons?</h3>
- An unpaired electron is an electron that doesn't form part of an electron pair when it occupies an atom's orbital in chemistry.
- Each of an atom's three atomic orbitals, designated by the quantum numbers n, l, and m, has the capacity to hold a pair of two electrons with opposing spins.
- Unpaired electrons are extremely uncommon in chemistry because an object carrying an unpaired electron is typically quite reactive. This is because the production of electron pairs, whether in the form of a chemical bond or as a lone pair, is frequently energetically advantageous.
- They play a crucial role in describing reaction pathways even though they normally only appear momentarily during a reaction on a thing called a radical in organic chemistry.
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The ph before the addition of any Koh is<u> 10.105.</u>
Concentration is the abundance of a constituent divided by way of the overall volume of an aggregate. several sorts of mathematical descriptions may be outstanding: mass concentration, molar concentration, variety concentration, and extent awareness.
After the addition of 50 ml KOH,
moles of KOH = 50 * 0.13 =<u> 6.5 mmol </u>
<u>moles </u><u>of HClO = 50 * 0.13 = 6.5 mmol </u>
occurred hydrolysis solution,
pH = 0.5(14 + pKa + log [base conjugate])
pH = 0.5(14 + (- log (4 * 10^-8)) + log (6.5/(50 + 50)))
pH = <u>10.105</u>
The concentration of a substance is the quantity of solute found in a given amount of solution. Concentrations are normally expressed in terms of molarity, defined because of the variety of moles of solute in 1 L of answer.
The Concentration of an answer is a measure of the quantity of solute that has been dissolved in a given amount of solvent or answer. A concentrated answer is one that has a rather huge quantity of dissolved solute.
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