Answer:
See the explanation below, please.
Explanation:
The elements of the periodic table that belong to the same group (each column) have similar physical and chemical properties. This is because they have the same number of electrons in their last electronic layer.
Example of electronic configuration of elements of GROUP IA:
Hydrogen: 1s ^ 1
Lithium: 1s ^ 2 2s ^ 1
Explanation:
Elements need a total of eight electrons to gain stability and look like a noble gas. So, they sometimes need sharing of two, four or even six electrons to complete their octate. So, they form double and triple covalent bonds. One more the reason is the interaction between the p orbitals of the combining atoms. for example A double bond, as in ethene H2C=CH2, arises from one combination of the s orbitals and one combination of the p_y orbitals.
Density = mass/volume
D = 40/80 = 0.5g
D= 0.5g
Answer: Option (E) is the correct answer.
Explanation:
A spontaneous reaction is defined as the process which tends to occur on its own. And, a non-spontaneous reaction is defined as a process for the completion of which we have to provide certain conditions.
For example, ice melting at 
is spontaneous primarily due to the increase in molecular disorder (dispersal of matter). Also, melting of ice is taking place on its own without any external force.
It is not necessary that all exothermic reactions will be exothermic in nature.
Thus, we can conclude that the statement all exothermic reactions are spontaneous, is false.
