Density=mass/volume=100g/20cm^3=5g/cm^3. The brick will fall in the lake, because its density is higher than that of water (1g/cm^3).
Answer:
N2+O2→2NO
Explanation:
Dalton’s atomic theory is based on law of constant composition and law of conservation of mass.
One of the postulates of this theory is that rearrangement of atoms occurs during a chemical reaction. In other words, only rearrangement of elements occurs during a chemical reaction and elements remain the same.
So, among the given, the following reaction undergoes rearrangement of elements.
N2+O2→2NO
SO, only the above reaction is possible as per Dalton’s atomic theory.
D
B
those are the correct answers
Magic number is any number in electron shells that suggest stability. It corresponds to total number of electrons in filled electron shells.
If an electron is having magic number, then it forms stable bonds.
Explanation:
The magic numbers are 2,10,18,36,54, 86 and 126. This refers to the total number of electrons that an electron can have when it is completely filled.
Atomic nuclei which carries either of these nucleons have high binding energy as compared to others. Hence, they have high stability. Bonds in such elements are more strong.
Radioactive decay of such elements is very slow.
Eugene Winger coined the term "magic number".