Answer:
0.86 moles of CO₂
Explanation:
Given data:
Number of atoms of CO₂ = 5.2×10²³ atom
Number of moles = ?
Solution:
Avogadro number:
The given problem will solve by using Avogadro number.
It is the number of atoms , ions and molecules in one gram atom of element, one gram molecules of compound and one gram ions of a substance.
The number 6.022 × 10²³ is called Avogadro number.
1 mole = 6.022 × 10²³ atoms
5.2×10²³ atom× 1 mol / 6.022 × 10²³ atoms
0.86 mol
true or false, water boils at 100°c
Answer:
This is true
Explanation:
What is the concentration of a stock solution if 20 mL was used to make 400 mL of a 1.44
M solution?
30 M
40 M
50 M
5M
Given :
Volume of stock solution, [tex]V_s = 20\ mL[/tex].
Volume of diluted solution, [tex]V_d = 400 \ mL[/tex].
Molarity of diluted solution, [tex]M_d = 1.44\ M[/tex].
To Find :
The concentration of the stock solution.
Solution :
We know, dilution factor is given by :
[tex]D.F=\dfrac{V_ {diluted}}{V_{stock}}[/tex] ....1)
and [tex]D.F= \dfrac{M_{stock}}{M_{diluted}}[/tex] ....2)
Putting volume in above equation, we get :
D.F = 400/20
D.F = 20
Putting value of D.F in equation 2) we get :
[tex]\dfrac{M_{stock}}{M_{diluted}} = 20\\\\M_{stock} = 20\times 1.44\\\\M_{stock} =28.8\ M[/tex]
The concentration of stock solution is nearest to 30 M.
Therefore, the correct option is 1) 30 M.
Which is greater 50 degree celcius or 50 degree fahrenheit?with solution plz.....
Answer: 50 degrees Celsius is hotter than 50 degrees F. 50 degrees Celsius is half way between freezing and boiling
Rubidium is a soft, silvery-white metal that has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, what is the average atomic mass of Rubidium?
The average atomic mass of Rubidium : 85.226 u
Further explanationIsotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
Mass atom X = mass isotope 1 . % + mass isotope 2.%
The abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, so the average atomic mass of Rubidium :
[tex]\tt the~average~atomic~mass=0.8\times 85+0.198\times 87\\\\the~average~atomic~mass=\boxed{\bold{85.226~u}}[/tex]
Solid carbon dioxide (CO2), also known as dry
ice, changes into a gas at room temperature. An
image of this change can be seen below.
Is this an example of a physical change? Why
or why not?
Answer:
yes
Explanation:
yes because the ice changes forms physically and can be changed back. not 100% sure tho
Answer:
shiii ion even know like i cant even tell u tha
Explanation:
bro 2 of my bruddas got locked up 2 days ago one of em got shot before the cops took him
if u know that answer i will mark has brainliest
Answer:
The clear liquid is less dense than the black liquid, which is why it floats on top. If the volume were different, you would visually see more clear liquid than black and vice versa.
The clear liquid is less dense than the black liquid
Answer:
A. The clear liquid is less dense than the black liquid
Explanation:
Since the clear liquid since on top of the black one it's density is less. Whatever liquid has a higher density will sink to the bottom of the flask.
What is it called when a rock is broken down into smaller pieces by ice, glacier or water ? Chemical weathering, physical weathering, deposition, pollution
Answer:
deposition I hope this helps!!
Explanation:
Answer:physical weathering
Explanation:
Identify the following structure as an atom, molecule, or compound molecule.
Hydrogen
A.atoms
B. molecules
C.compound molecules
Answer:
A
Explanation:
The answer is A because Hydrogen is an Atom consists of 1 electron only.
Good luck
A diver's tank contains helium at 924 psi,
nitrogen at 1456 psi and oxygen. The total
pressure is 2803 psi. What partial pressure is
exerted by the oxygen?
what are the energy transformations taking place in your alarm clock
Answer:
Explanation:
The clock now has potential energy. When the alarm rings, the potential energy is converted into kinetic energy and sound energy.
Alarm clock runs due to the electrical energy. Due to the electric current, the electric motor rotates the blade. It means that the electrical energy is converted into mechanical energy.
The mechanical energy finally generates vibrations which cause sound.
Thus, energy transformation which takes place in alarm clock will follow the order-
Electrical to mechanical to sound.
Criminalist Julie Sandel is investigating a series of threatening notes written in pencil and sent to a local politician. A suspect is arrested and Julie directs the suspect to prepare writing samples to compare to the writing on the notes. She has the suspect sit at a desk in an empty office and gives him a pen and a piece of paper. She begins to read one of the notes and asks the suspect to write the words she dictates. After reading about half a page, she stops, then dictates the same part of the note a second time for the suspect. At one point, the suspect indicates that he does not know how to spell one of the words, so Julie spells it for him. After completing the task, Julie takes the origi- nal notes and the dictated writing from the suspect to a document examiner. What mistakes, if any, did Julie make?
Answer:
See explanation
Explanation:
Julie Sandel, the Criminalist made several mistakes in handling this investigation. They include;
It is true that handwriting can be deduced by comparing a suspects's handwriting to the questioned document, however Julie made a mistake by not making the suspect to write many pages. The suspect may intentionally decide to change his/her hand writing. This trick can be neutralized by asking the suspect to write several pages.
Secondly, the suspect ought to have been given a pencil and paper similar to the one used to write the threatening document. Rather, Julie gave the suspect a pen.
Thirdly, the suspect only wrote half a page instead of a full page. Secondly, Julie took only two exemplars when she should have taken more.
She should not have dictated the spelling of any word to the suspect. The examiner is not supposed to do that.
The threatening documents should have first been shown to the document examiner before taking the exemplars.
What is the location of elements in the periodic table related to?
Answer:
.
Explanation:
An element's location in the periodic table is largely depending on its electrons. The number of valence shell electrons determines its group, and the type of orbital in which the valence electrons lie in determines the element's block. Sometimes during these groups there are more like the alkali metals the non metals and gases :)
true or false, vaporization that occurs at the surface of a liquid is called evaporation
Answer:
True
Explanation:
Vaporization that happens below the surface is boiling, above the surface is evaporation :)
Answer:
True
Explanation:
it evaporates because of the temperature difference
Science hmk due tmr morning need help!! pls answer all 3 and number which one is which for example...
1.j
2.j
3.j
Observe: Look at the red lithium atom and the blue oxygen atom. Recall that most atoms are stable when their outermost ring has eight electrons. (Some atoms, such as lithium and beryllium, are stable when their outermost ring has two electrons.)
How many electrons will the lithium atom give up to become stable?
1. eight
2. seven
3. two
4. one
Answer:
4. one
Explanation:
6CO2 + 6H20 --> C6H12O6 + 602
What is the total number of grams of water needed to make 6.2 moles of CoH1206?
79.5 g
402.9
670.2 g
381.2 g
what happens if the temperature of a system at equilibrium is increased?
The elements on the Periodic Table of the Elements are arranged in order of increasing
Answer: The Atomic Number increases. Hope this helps!!!
Explanation:
Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass.
Answer:
The Atomic number increases....
Explanation:
Duh
How are Earth's continents related?
Please help due at 11:45!
What is the mass and volume of the nucleus relative to the size of the atom?
Answer:
The atom with the smallest mass is the hydrogen atom; its mass is about 10-27 kg. The masses of other atoms go up to about 200 times this. The nucleus of an atom is about 10-15 m in size; this means it is about 10-5 (or 1/100,000) of the size of the whole atom.
Using the Assignment: Locating the Epicenter, What was the length of the radius of the circle of from the Buenos Aires station? (in cm)
Question 1 options:
3.2 cm
4.8 cm
5.76 cm
8 cm
Show your work with good use of units, rounding, and significant figures. [Hint: it is good practice to show the value of your answer before you round off to the final answer with the correct significant figures!]
(8 points) How much heat is required to convert 10.00 g of ice at –20.00°C to water at 25°C. The specific heat of ice is 2.09J/g°C; the specific heat of water is 4.182 J/g°C; the heat of fusion is 333.0 J/g.
Group of answer choices
Heat required : 4.8 kJ
Further explanationThe heat to change the phase can be formulated :
Q = mLf (melting/freezing)
Q = mLv (vaporization/condensation)
Lf=latent heat of fusion
Lv=latent heat of vaporization
The heat needed to raise the temperature
Q = m . c . Δt
1. heat to raise temperature from -20 °C to 0 °C
[tex]\tt Q=10\times 2.09\times (0-(-20)=418~J[/tex]
2. phase change(ice to water)
[tex]\tt Q=10\times 333=3330~J[/tex]
3. heat to raise temperature from 0 °C to 25 °C
[tex]\tt Q=10\times 4.18\times (25-0)=1045~J[/tex]
[tex]\tt Q~tot=418+3330+1045=4793~J\rightarrow rounding~and~2~sig~figs=4.8~kJ[/tex]
are Li, Na and K in the same group
Answer: Yes, they are.
Explanation:
Yes, they are. Li, Na, and K are referring to Lithium, sodium, and potassium.
They are all belonging to the same group which is called the alkali metals group.
They are having the same number of valence electrons i.e. 1.
This group of the alkali metals are considering tree more metals in it which are Rb, Cs, and Fr.
THIRTY POINTS I NEED HELP HURRY What is the volume of the cone?
Answer:
V=πr2h 3
Explanation: I would give more but need more i information
Answer:there u go
Explanation:The volume V of a cone with radius r is one-third the area of the base B times the height h . Note : The formula for the volume of an oblique cone is the same as that of a right one. ... If the heights of a cone and a cylinder are equal, then the volume of the cylinder is three times as much as the volume of a cone
Why are you able to smell things across a room or form great distances
Answer:
We smell hot food from distance because of the diffusion process. Diffusion is the spreading out and intermixing of particles From one substance into another substance due to the movement of particles.
Explanation:
How many grams are there in 2.34x10^23 atoms of Cu?
The mass of the 2.34 × 10²³ atoms of copper is equal to 24.68 grams.
What is Avogadro's number?The Avogadro constant can be defined as the proportionality factor that the number of constituent particles in a sample with the amount of substance.
Avogadro’s number can be described as a dimensionless number that represents the number of entities in one mole of any substance. These elementary entities can be molecules, atoms, ions, electrons, or protons, etc.
Avogadro’s constant has a value approximately equal to 6.022 × 10²³ mol⁻¹.
Given, the number of atoms of copper = 2.34 × 10²³
The atomic mass of Cu Copper = 63.5 g/mol
So 6.022 × 10²³ atoms of Cu have mass = 63.5 g
Then 2.34 × 10²³ Cu atoms will have mass = [tex]\frac{63.5 \times 2.34 \times 10^{23}}{6.02 \times 10^{23}}[/tex] = 24.68 g
Therefore, 24.68 grams of Cu are there in 2.34 × 10²³ atoms of Cu.
Learn more about Avogadro's number, here:
brainly.com/question/11907018
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Using the model of the periodic table, which element pictured represents an unreactive gas?
Answer:
2
Explanation:
Nobel gasses are not reactive and are the far right group on the periodic table. This is because they have a full valence electron shell which is the most stable electron configuration. Most reactions occur in order for an atom to fill its valence shell and since they already have a full valence shell there is no reason for them to react.
What do you think caused this land formation ?
Which of the following sets of descriptors matches the molecule below?
Image of two oxygen atoms bonded together to form O2.
A. Compound, allotrope, double bond, one element
B. Molecule, compound, single bond, allotrope
C. Simple structure, diatomic, double bond, molecule
D. Giant structure, single bond, compound, one element
Simple structure, diatomic, double bond, molecule. Hence, option C is correct.
What is a compound?A pure substance made up of two or more different elements combined chemically in a fixed ratio is called a compound.
[tex]O_2[/tex] is a covalent molecule because each oxygen atom needs two valence electrons to complete its octet. To meet this need each oxygen atom shares two of its electrons with the other oxygen forming a strong oxygen-oxygen double-shared covalent bond.
Hence, option C is correct.
Learn more about compounds here:
https://brainly.com/question/14782984
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another science question plz answer ASAP b/c its timed
Answer:
D
Explanation: