Answer:
D. It is a chemical reaction because the total mass remains the same when new substances are formed.
Explanation:
A chemical reaction is represented by a chemical equation which show the reactant and products. Reactants are written on left side of arrow while products are written on right side. The number of atoms are remain same however arrangement of atoms is different on both side.
For example:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen. The number of atoms are same on both side however arrangement of atoms is different.
While in case of nuclear reaction small change in mass take place.
Answer: D:wavelenght
Explanation: Students will understand that shorter wavelengths have higher frequency and energy.
526 L O2 x 1 mol O2 / 22.4 L = 23.5 mol O2
Answer:
Calcium chloride react with aluminum to produce calcium and aluminum chloride. This reaction takes place at a temperature of 600-700°C.
CaCl2+F2 -> CaF2 + Cl2
Answer: Option (d) is the correct answer.
Explanation:
As it is known that like dissolves like. So, water being a polar compound is able to dissolve only polar compounds.
Hence, a compound that is ionic or polar in nature will readily dissolve in water. Whereas non-polar compounds will be insoluble in water.
As 
is a non-polar compound. Hence, it is insoluble in water.
On the other hand, 
is a polar compound due to difference in electronegativity of chlorine and carbon atom there will be development of partial charges. Hence, there will be dipole-dipole forces existing between them.
Whereas 
is an ionic compound and it will readily dissociate into ions when dissolved in water. Also, there will be ion-dipole interactions between sodium and nitrate ions.
Hence, will readily dissolve in water.
Thus, we can conclude that the compounds correctly arranged in order of increasing solubility in water are < < .
