Answer:
An atom is a particle of matter that uniquely defines achemical element. An atom consists of a central nucleus that is usually surrounded by one or more electrons. ... The nucleus is positively charged, and contains one or more relatively heavy particles known as protons and neutrons. A proton is positively charged.
<u>Answer:</u> The mass of calcium chloride present in given amount of solution is 87.5 g
<u>Explanation:</u>
We are given:
Mass of solution = 277.8 grams
Also, 31.5 % (m/m) of calcium chloride in water. This means that 31.5 g of calcium chloride is present in 100 g of solution.
To calculate the mass of calcium chloride in the given amount of solution, we use unitary method:
in 100 g of solution, the mass of calcium chloride present is 31.5 g
So, 277.8 g of solution, the mass of calcium chloride present is 
Hence, the mass of calcium chloride present in given amount of solution is 87.5 g
Answer:
2.5×10^-7mol/dm^3
Explanation:
Firstly convert the cm^3 to dm^3
200×1000=200000dm^3
Calculate the g/dm^3
2/200000=0.00001g/dm^3
To calculate mol/dm^3
Mol/dm^3=mass given\molar mass
=0.00001/40
=2.5×10^-7mol/dm^3
D & e represent the same element
The one from the cupboard because it is warmer (has more thermal energy) than the one from the refrigerator. When a liquid becomes warmer, the solubility of a gas becomes lower. Therefore, there is already more CO2 in its gaseous state when the soda is warm.
