Answer:
Explanation:
Dmitri Mendeleev developed a chart-like arrangement of the elements called the Periodic Table ______ . He stated that if the elements were listed in order of increasing atomic mass______, their properties repeated in a regular manner. He called this the periodicity of properties ______ of the elements. The arrangement used today differs from that of Mendeleev in that the elements are arranged in order of increasing atomic number______. Each horizontal row of elements is called a(n)period ______. Each vertical column is called a(n) column_____, or , because of the resemblance between elements in the same column, a(n) __group____.
Given, the density of water is 0.9975 g/ml. Density of water is mass of water per unit volume. Mass of 1 ml of water supposed to be 0.9975 g from density of water. So, mass of 10 ml of water is (0.9975 X 10) g= 9.975 g. From graduated cylinder, mass of 10 ml water is measured to be 9.955 g. So, error for mass of 10 ml water= (9.975-9.955)=0.02 g. Percentage of error for 10 ml water is 
= 0.2. Error in the mass for the 10 ml of water is 0.2 %.
Answer: No
Explanation:
Firstly, the molar mass of the dissolved solid is not given. This is necessary to calculate the number of moles present in solution. Secondly, solubility always has to do with temperature and the specified temperature is 27°c and not 21°c. This makes it impossible to calculate the solubility at 21°c. Further information must supplied before the solubility at 21°c can be accurately calculated.
The formula of Cobalt oxide is ZnO.
2Co(s) + O2(g) ----> 2CoO(s)
It is in solid state. It contains one atom of Cobalt and one atom of Oxygen.It is basic in nature because it is a metal oxide. It is black coloured powder. As we know that metal oxides are basic in nature.
CoO(s) + H2O (l) ---> Co(OH)2
It's solution turns red litmus paper into blue which proves that it is a base.
