Explanation:
To convert moles to particles or grams to particles, let us have a firm understanding of what a mole is.
A mole is the unit of measuring quantity of particles.
It is the amount of substance that contains the Avogadro's number of particles.
The particle can be atoms, molecules, formula units, electrons, protons, neutrons, etc.
So, to convert from moles to particles;
1 mole of a substance contains 6.02 x 10²³ particles
To convert from grams to particles;
First convert to moles;
number of moles =
So, 1 mole of a substance contains 6.02 x 10²³ particles
Answer is (b) , because a chemical change happened
Answer:
Final temperature = 
Explanation:
Given that,
Heat added, Q = 250 J
Mass, m = 30 g
Initial temperature, T₁ = 22°C
The Specific heat of Cu= 0.387 J/g °C
We know that, heat added due to the change in temperature is given by :

Put all the values,

So, the final temperature is equal to
.
Answer:
hydrated ferric oxide is ferric hydoxide sol and is positively charged. When aqueous solution of NaCl is added to it,the Cl- ions neutralise the positive charge on the sol particles. In the absence of charge, brown precipitate is formes due to colloids can be coagulation of particles.Nov 11, 2020
Explanation: hope this help