Which of the following would not be considered renewable forms of energy? a. nuclear reactors using pu-239 b. burning coal c. photovoltaics d. geothermal energy e. wind energy (can be more than one answer.)

Answer : The correct answer is A. Nuclear reactors using Pu-239

B. burning coal

The sources which are not renewable are known as "non- renewable sources of energy .

Non - renewable sources are those which get expired after rapid use and can never be reproduced . These sources replenishes in very long time . Examples : Coal , petrol or fuels etc .

1) Nuclear reactors using Pu-239 : Nuclear reactors uses radioactive elements like uranium , plutonium etc , which are present in limit . after frequent use of these elements , they will vanish off , Hence we can say nuclear reactors are Non renewable source of energy .

2) Burning coal : Coal is used as one of the major source of fuel . On rapid utilization of coal they will finished from earth . It takes thousand of year for formation of coal . Hence , it is a Non -renewable source .

3) Photo-voltaic cell: These are cells which used solar energy . Solar energy is obtained from sun . Hence solar energy is renewable source of energy so is the photo voltaic cell .

4) Geothermal energy : Geothermal energy is source of energy that is extracted from earth's thermal energy . Since thermal energy of earth is present in very large amount and can be reproduced , hence it renewable source of energy .

5)Wind energy : Wind energy is source of energy that is obtained from wind. And wind is renewable source so the wine energy too .

Consequently , we can say only two of them " Nuclear reactors and burning of coal " are Non renewable force of energy .

d: the voltage of the secondary coil is less than that of the primary coil.

im not suree sorry if wrong

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.