Answer:
No moon has no light.
Explanation:
It only reflects the light coming from the sun. Only star produces light and moon is a satellite that revolvs around the earth.
Answer:
Calcium Nitrate is made up of three different elements and contains a total of nine atoms. This compound's formula is Ca(NO3)2. There is one calcium atom, two nitrogen atoms, and there are six oxygen atoms in calcium nitrate
Explanation:
Mole = 0.5 = n/NA
n = no. of molecule
NA = avogadro number = 6.023x 10^23
so
N/NA = 0.5
N = 0.5 x 6.023 x 10^23
N = 3.0115 x 10^23
Part (a):
Chalk has the chemical formula: CaCo₃
From the periodic table:
mass of Ca = 40 grams
mass of Co = 58.9 grams
Therefore:
molecular weight of chalk = 40 + 3(58.9) = 216.7 grams
Part (b):
Advantages of M<span>andeleev's periodic table:
1- Could predict the properties of elements easily based on its position in the periodic table
2- Elements were arranged systematically in order of increasing atomic mass which helped in the study and classification of elements
3- Even after the discovery of noble gases, no major changes needed to be done to the periodic table. Noble gases were inserted easily
4- He left room for other undiscovered elements based on his systematic approach in writing the table
Hope this helps :)</span>
