Answer:
18.4 g
Explanation:
M(He) = 4.0 g/mol
4.6 mol * 4.0 g/ 1 mol = 18.4 g
the alkaline eart metal s are
Beryllium
Magnesium
calcium
Strontium
barium
out of these Magnesium reacts with oxygen and produces bright light due to formation of MgO
all other metals also form oxides but the oxide of Mg is brightest
That power is electricity. And we use that in our daily life! Without nuclear power plants producing elextricity to power your computer, you would not have been able to ask this question on Brainly :) :P
Answer:
The energy of the photon is directly proportional to the frequency of the light emitting the photon.
Explanation:
Energy of the photon is given by expression:

E = Energy associated with the photon
= frequency of the light
h = Planck's constant =
c = speed of the light in vacuum = constant
=Wavelength of the photon

The energy of the photon is directly proportional to the frequency of the light emitting the photon.
Answer:
(a) Dissolving sugar in water ⇒ physical change
(b) Crushing rock salt ⇒ physical change
(c) Burning sulfur ⇒ chemical change
(d) Digesting a chili dog ⇒ chemical change
Explanation:
<em>Physical changes</em> are those in which the substance does not alter its composition. They only involve changes of states of matter and the chemical substance is stil the same after the change occurs. By other hand, <em>chemical changes</em> are those in which new subtances are formed. So, the subtance is not the same after the change.
(a) Dissolving sugar in water ⇒ <em>physical change</em>; because we obtain a solution of sugar in water (sugar is stil sugar).
(b) Crushing rock salt ⇒ <em>physical change</em>; because we obtain crushed salt, but the chemical composition of the salt is not altered.
(c) Burning sulfur ⇒ <em>chemical change</em>; because sulfur is oxidized (chemical reaction) and new compounds are formed, for example sulfur dioxide.
(d) Digesting a chili dog ⇒ <em>chemical change</em>; because the digestion process is produced by the action of hydrocloric acid, and new compounds are formed.