Answer:
Group 18th
Explanation:
The group 18th of periodic table which is composed of Noble gases mainly was missing from the Mendeleev's periodic table. The reason for this is that Noble gases are least reactive, therefore, it was difficult to predict such elements which do not react with other elements.
Answer:
Mole of the H2O = 4.5
Number of molecules =4.5 multipled by avogadro's number.
Answer:
The rate of acceleration is 5.
Explanation:
In order to calculate acceleration we need to divide the force by the mass.
Acceleration = net force/mass
In this case, it would be 20/4. Simplify that and we get 5.