The correct answer is B. Chewing in the mouth breaks food into small pieces.
Explanation:
In physical changes, substances do not change their chemical composition or properties but only physical features such as this. This occurs during the chewing because the action of chewing only makes food to be broken down in smaller pieces but does not change its identity, composition, or properties. This does not occur once the food is in contact with saliva, the acid in the stomach, etc. because in these cases, the food reacts with other substances and a chemical reaction occurs, which changes food's identity and composition.
Answer:
78.75g
Explanation:
The density of diamond is the mass of diamond per unit of its volume. The density of a substance is calculated using the formula:
Density (g/cm^3) = mass (g) / volume (cm^3)
According to the question, the density of diamond= 3.15g/cm^3, volume of diamond= 25cm^3, mass = ?
Hence, to calculate the mass, we say;
Mass = Volume × density
Mass = 25 × 3.15
Mass = 78.75
Therefore, the mass of diamond is 78.75grams.
There are three things you can do to dissolve the salt in water:
1) Stir the solution - you increase the rate at which water molecules will come in contact with the salt crystals
2) Grind the salt - the surface area of the salt will increase thus the contact area between ionic lattice of the crystal that can interact with water, is bigger
3) Increase the temperature - this will increase even more the rate of the solvation by increasing the kinetic energy of the particles
A unit cell is a simplest repeating unit in a crystal in which particle are freely vibrating
Sodium chloride having face centered cubic lattice in which sodium and chloride ion are arranged and vibrating.
The sodium ion are arranged on eight corners of the cube whereas they are also present on all the six centres of all six faces.
Thus, number of Na+ ion
Hence total of 14 sodium ions are present in NaCl lattice.
Exergonic reactions release energy; endergonic reactions absorb it.