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.
Answer:
Final state of the hydrogen atom is the state where principle quantum number n = 2
Explanation:
When a photon of light having wavelength of 93·73 nm falls on hydrogen atom, the atom absorbs an energy of (h×c)÷93·73 nm
as Energy E = (h×c)÷wavelength
where
h is the Planck's constant
c is the speed of light in vaccum which is 3× m/s
Energy that is released is (h×c)÷410·1 nm
Let the principle quantum number of the final state of the hydrogen atom be n
According to the Bohr's principle
Energy difference between two states = ΔE = ( (1÷n²) - 1)
as the principle quantum number of the final state is n and principle quantum number of the initial state is 1
∴ ΔE = (h×c)((1÷93·73 nm) - (1÷410·1 nm))
( (1÷n²) - 1) = (h×c)((1÷93·73 nm) - (1÷410·1 nm))
( ( (1÷n²) - 1)) ÷ (h×c) = (1÷93·73 nm) - (1÷410·1 nm)
∴ n≈2
∴ Principle quantum number of the final state is 2
Answer: f = 760 Hz
Explanation: speed = frequency · wavelength v = fλ.
frequency f = v/ λ = 380 m/s / 0.50 m = 760 Hz
I hope I’m not wrong on this one but I think chemical changes
Reasoning: I took culinary and we talked more on chemistry than culinary
If I’m wrong sorry
The correct answer is letter A. We use the formula, <span>v=vo + at to get the answer.</span>
<span>
v=vo + at </span>
<span>v=0 + (9.8)(8) </span>
<span>v=78.4 </span>
<span>y=1/2(vo + v)t </span>
<span>y=1/2(78.4)(8) </span>
<span>y=1/2(627.2) </span>
<span>y=313.6m
</span>