There are 2 significant figures
Answer:
Energy of photon is 34.45 ×10⁻¹⁹ J.
Explanation:
Given data:
Frequency of photon = 5.2×10¹⁵ s⁻¹
Plancks constant = 6.626×10⁻³⁴ Js
Energy of photon = ?
Solution:
Formula:
E = h.f
by putting values,
E = 6.626×10⁻³⁴ Js × 5.2×10¹⁵ s⁻¹
E = 34.45 ×10⁻¹⁹ J
Thus, energy of photon is 34.45 ×10⁻¹⁹ J.
Answer:
Explanation:
Hello!
In this case, since the sulfuric acid and sodium hydroxide react in a 1:2 mole ratio, given the reaction, we realize they have the following mole ratio at the equivalence point:
Which in terms of concentrations and volumes is:
Thus, we can plug in the volume and concentration of acid to find the moles of base:
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Hello there!
Question: Which of the following is most likely an indication of a chemical change?
Answer Choices:
A. A loud sound when an MP3 player is turned on.
B. A loud sound when someone claps their hands.
C. A loud sound when a starter's pistol is fired at a race.
D. A loud sound when a large object falls to the ground.
Correct Answer:
C. A loud sound when a starter's pistol is fired at a race.
Reasons:
A would not be correct since an MP3 player is a mechanical object and does not mix any substances that create a reaction.
B would not be correct since clapping hands causes a loud sound due to two forces slamming together and causes a disturbance in the air.
D would not be correct since a large object falling to the ground does not indicate any chemical reactions or changes since its merely the result of a mass hitting another mass.
C would be correct since the gunpowder mixes with other substances inside the pistol's chamber and causes and explosion, and explosions are part of a chemical reaction indicators.
Answer:
A. Chlorine
Explanation:
Chlorine has 17, Hydrogen has 1, Oxygen has 8, Sulfur has 16.
