Why is john dalton known as the originator of atomic theory? a. he was the first to propose that matter is made of atoms. b. he proved that atoms are divisible in nature. c. he based his theory on philosophical assumptions. d. he could scientifically explain the theory of atoms.

Option A: He was first to propose that matter is made of atoms.

John Dalton proposed that matter is made up of indivisible atoms. Here atoms are like building blocks of matter and can not be further destroyed. For an element, all atoms are identical but for different elements, they can vary in mass and size. Also, in compound, atoms of elements always combine in fixed ratio by mass.

Option B is incorrect because according to him atom is indivisible as subatomic particles were not discovered at that time.

Option C and D are also incorrect as he does not made any philosophical assumptions and also he could not scientifically explain his theory of atoms.

alkaline metals are lithium, sodium, rubidium, potassium, cesium and francium.

alkali metals have electronegativity from 0.7 to 1, lowest in periodic table of elements, which means that alkali metals (i group in periodic table) has positive oxidation number in compounds.

electronegativity is a chemical property that describes the tendency of an atom to attract a shared pair of electrons towards itself.

alkaline metals (far left in main group) have lowest ionizations energy and easy remove valence electrons,

for example, potassium is the alkali metal and has a single valence electron in the outer electron shell.

electron configuration of potassium is: ₁₉k 1s²2s²2p⁶3s²3p⁶4s¹.

they can not exist alone in nature, because they are very reactive.

hurricanes form when warm, moist air from the ocean surface quickly rises into the atmosphere and forms storm clouds and rain. when the clouds are formed, heat is released which warms the cool air in the upper regions of the atmosphere so that the cycle can continue. which two phases of the water cycle are repeated in this process?