Answer:
4.88 x 10²⁴atoms
Explanation:
Given parameters:
Number of moles of oxygen = 8.1moles
Problem:
To find the number of atoms in 8.1moles of oxygen.
Method in solving the problem:
We know that a mole of a substance contains Avogadro’s number of particles which is 6.02 x 10²³
The particles can be molecules, atoms, etc.
Solution:
From the concept of mole,
Number of atoms =
number of moles x 6.02 x 10²³
Number of atoms = 8.1 x 6.02 x 10²³
Number of
atoms of oxygen = 48.8 x 10²³ atoms
= 4.88 x 10²⁴atoms
Answer:
Human ears can hear sound waves that vibrate in the range from about 20 times a second (a deep rumbling noise) to about 20,000 times a second (a high-pitched whistling). (Children can generally hear higher-pitched sounds than their parents, because our ability to hear high frequencies gets worse as we get older.) Speaking more scientifically, we could say that the sounds we can perceive have a frequency ranging from 20–20,000 hertz (Hz). A hertz is a measurement of how often something vibrates and 1 Hz is equal to one vibration each second. The human voice makes sounds ranging from a few hundred hertz to a few thousand hertz.
Suppose you could somehow hit a drum-skin so often that it vibrated more than 20,000 times per second. You might be able to see the skin vibrating (just), but you certainly couldn't hear it. No matter how hard you hit the drum, you wouldn't hear a sound. The drum would still be transmitting sound waves, but your ears wouldn't be able to recognize them. Bats, dogs, dolphins, and moths might well hear them, however. Sounds this like, with frequencies beyond the range of human hearing, are examples of ultrasound.
Infrasonics, vibrational or stress waves in elastic media, having a frequency below those of sound waves that can be detected by the human ear—i.e., below 20 hertz. The range of frequencies extends down to geologic vibrations that complete one cycle in 100 seconds or longer.
<span>Calculate the standard entropy change for the dimerization of NO2: 2NO2(g)→N2O4(g)at 298 K, if
Sâ—¦ â†Hâ—¦f J/K·mol
NO2(g) 240.06 33.18
N2O4(g) 304.29 9.16
Answer in units of J/K·mol
AP Chemistry - DrBob222 Tuesday, October 29, 2013 at 8:53pm
See your other posts below.
AP Chemistry - fg Monday, April 4, 2016 at 4:19pm
dg4354
2242342
1111
AP Chemistry - Eman Monday, April 25, 2016 at 11:19am
-175.8 j/k.mol</span>
Answer:
B. an absolute age only
Explanation:
An absolute age is the exact numerical age of an object. Absolute ages are usually obtained from dating of the object using the radioactive materials they contain. The radioisotopes in the objects acts as the clock in it. If one says an object is 9 million years old, it is an absolute age.
Relative dating depicts age based on the occurrence of an event in relation to another. If one says, the age of an object is between the Jurassic and Triassic, it is a relative age.
In science, both absolute and relative dating are related.
Answer:
In a <u>7-step</u> scientific method, Spongebob utilized the <u>6th</u> step when He wrote a brief summary of the investigation, and Spongebob utilized the <u>7th </u>step when He also determined that his hypothesis statement was not right and explained why it wasn't right by providing evidence from the investigation.
Explanation:
Scientific Methods are organized ways employed by scientists to tackle problems by providing solutions to the problem or make hypotheses to which other scientists build on to provide solutions to the problem.
The steps of the scientific method are:
Step 1- Understand the Problem
Step 2- Make research
Step 3- Hypothesis.
Step 4- Conduct an experiment to test the hypothesis
Step 5- Observations.
Step 6-Results/Conclusion.
Step 7- Communicate your research
When Spongebob wrote a brief summary of the investigation, which means he had already conducted an experiment and had already made necessary observations and data collection, so he was at step 6. At step 6, he had analyzed the data collected.
When Spongebob determined that his hypothesis statement was not right and explained why it wasn't right by providing evidence from the investigation, then he was at the final step of the scientific method. Step 7 tells whether the hypothesis is true or false.
