The first pesticides relied on natural chemicals, such as those taken from chrysanthemum flowers is true
Answer:
Option (D) freezing point depression
Explanation:
Calcium chloride is added to the roadways after a snowstorm because it reduces the freezing point of the ice. Further more, it has been observed that the calcium chloride also produces enough heat which enhances the melting of the ice as it produces an exothermic reaction.
Answer:
Moles=2.04×10^(-6)
Explanation:
No. Of moles=no. Of particles/ Avogadro's no
(Where no. Of particles may be atoms molecules or compounds)
Moles=1.23×10^18/6.022×10^23
Moles=0.204×10^(-5)
Moles=2.04×10^(-6)
All of the above. If you are going to narrow it down, it would be high voltage and radioactivity.
Answer:
Potassium
1s2 2s2 2p6 3s2 3p6 4s1
Explanation:
The atom having only one electron its outermost shell must belong to an element in group one of the periodic table.
Having noted that, we proceed to find out what element in group one that has the atom just described in the question.
That atom must belong to an element in the fourth period. The only group 1 element in the fourth period is potassium.
The electron configuration of potassium is;
1s2 2s2 2p6 3s2 3p6 4s1
