Answer:
162.349
Explanation:
(.3060 * 159.37) + (.1579 * 162.79) + (.5361 * 163.92) = 162.349
A laser pointer used in the classroom emits light at 5650 Å, at a power of 4.00 mW. (One watt is the SI unit of power, the measure of energy per unit of time. 1 W = 1 J/s). How many photons are emitted from the pointer in 115 seconds?
Answer:
n = 1.3 x 10¹⁸ photons
Explanation:
First we need to calculate the amount of energy released in given time:
E = Pt
where,
E = Energy = ?
P = Power = 4 mW = 0.004 W
t = time = 115 s
Therefore,
E = (0.004 W)(115 s)
E = 0.46 J
Now, this energy can be given in forms of photons as:
E = nhc/λ
where,
n = No. of photons = ?
h = Plank's Constant = 6.626 x 10⁻³⁴ J.s
c = speed of light = 3 x 10⁸ m/s
λ = wavelength of light = 5650 x 10⁻¹⁰ m
Therefore,
0.46 J = n(6.626 x 10⁻³⁴ J.s)(3 x 10⁸ m/s)/(5650 x 10⁻¹⁰ m)
n = (0.46 J)/(3.5 x 10⁻¹⁹ J)
n = 1.3 x 10¹⁸ photons
Answer:
1.308 x 10¹⁸ photons were emitted from the laser pointer.
Explanation:
Given;
wavelength of the photon, λ = 5650 Å = 5650 x 10⁻¹⁰ m
power emitted by the source, P = 4 mW = 4 x 10⁻³ W
time of photon emission, t = 115 s
The energy of a single photon is given by;
E = hf
f = c / λ
[tex]E = \frac{h c }{\lambda}[/tex]
where;
c is speed of light = 3 x 10⁸ m/s
h is Planck's constant = 6.626 x 10⁻³⁴ Js
[tex]E = \frac{(6.626 *10^{-34}) (3*10^8) }{5650*10^{-10}}\\\\ E = 3.518*10^{-19} \ J[/tex]
Energy of the source (laser pointer) = P x t
= (4 x 10⁻³ W) (115 s )
= 0.46 J
If no energy is lost, then emitted energy by the source must be equal to total energy of then photons;
[tex]E_T = n E_{photon}\\\\n = \frac{E_T}{E_{photon}}\\\\n = \frac{0.46}{3.518*10^{-19}}\\\\n = 1.308*10^{18} \ photons[/tex]
Therefore, 1.308 x 10¹⁸ photons were emitted from the laser pointer.
Cuci
what is the formula?
Answer:
Copper(I) chloride, commonly called cuprous chloride, is the lower chloride of copper, with the formula CuCl. The substance is a white solid sparingly soluble in water, but very soluble in concentrated hydrochloric acid. Impure samples appear green due to the presence of copper(II) chloride.
Explanation:
Please mark me brainliest
An advertisement for a new fish food claims that lab studies show that fish grew three inches in three weeks while eating the food. Travis wondered if the food was worth the extra cost.
Answer: To evaluate the claim in the advertisement, Travis should look at the data for the control group to see how much the fish grew without the new food.
Explanation:
an object has a mass of 14g and a volume 3.5 mL. what is the density of the object ?
Given :
Mass of object , M = 14 g .
Volume of object , V = 3.5 mL .
To Find :
The density of the object .
Solution :
Density of an object is given by :
[tex]Density=\dfrac{Mass}{Volume}\\\\\rho=\dfrac{M}{V}\\\\\rho=\dfrac{14}{3.5}\ g/mL\\\\\rho=4\ g/mL[/tex]
Therefore , the density is 4 g/mL .
Hence , this is the required solution .
2. You are tasked with calculating the average weight of kindergartners in a class of
21 students. Their weights range from a low of 40.5 lbs to a high of 58.6 lbs.
How many significant figures should be in the average that you find?
Give the charge on the transition metal of each of the following compounds:
A. Au2SO4
B. Fe2(CrO4)3
C. Zn(OH)2
Enter your answer as +1, +2, etc.
Au
type your answer...
Fe
type your answer...
Zn
type your answer...
In Au₂SO₄, the charge on each gold atom is +3.
The charge on the transition metal gold (Au) in Au₂SO₄ can be determined by considering the overall charge of the compound and the charges of the other ions present. In this case, the sulfate ion carries a charge of -2.
Charge on Au: +3
In Fe₂(CrO₄)₃, the transition metal iron (Fe) is present. The compound contains two iron atoms. To determine the charge on each iron atom, the charges of the other ions in the compound. The chromate ion carries a charge of -2, and the compound as a whole is neutral.
Charge on Fe: +3
The transition metal zinc (Zn) is present in Zn(OH)₂. To determine the charge of the zinc ion, to consider the charges of the other ions. The hydroxide ion (OH-) carries a charge of -1. Since there are two hydroxide ions, their combined charge is -2.
Charge on Zn: +2
To learn more about atom, follow the link:
https://brainly.com/question/1566330
#SPJ6
You heat 51 grams of magnesium over a Bunsen burner for several minutes until it reacts with oxygen in the air. Then you weigh the resulting product and see that it is now 53 grams. How does this happen without breaking the Law of Conservation of Mass?
Answer:
The mass was there all along, it was just in the air. The weight of the oxygen from the air is not weighed in the beginning, only at the end as part of the product, making it seem like there is a total mass change.
I WILL mARK U BRAINLLYIST
Scientists in a particular fieScientists in a particular field strive for the same quality of work because they know their peers will be reviewing their scientific claims. What does this review process help ensure?
standards of the profession
publication in scientific journals
resistance to new information
access to university databases
indigestion tablets neutralise acid in the stomach. what does this tell you about indigestion tablets?
Answer:
It is basic.
Explanation:
Bases can neutralize acids.
Identify the characteristics of a good recrystallization solvent. Select one or more: Dissolves a chemical sample well at high temperatures. Is not an organic liquid with a low boiling point. Does not dissolve a chemical sample well at low temperatures. Does not dissolve a chemical sample well at high temperatures. Dissolves a chemical sample well at low temperatures. g
Answer:
Dissolves a chemical sample well at high temperatures.
Does not dissolve a chemical sample well at low temperatures.
Explanation:
Recrystallization involves the dissolution of the solute in a solvent at high temperature. As the solution cools, it becomes saturated and the solute crystallizes out of the solution.
A good recrystallization solvent must only dissolve the solute at high temperature and must not dissolve it at low temperature. Hence, these are the two conditions required for any good recrystallization solvent.
To what volume (in mL) would you need to dilute 25.0mL of a 1.45 m solution of Kcl to make a 0.0245m solution of KCl
Answer:
The answer is
1479.60 mLExplanation:
In order to calculate the volume needed we use the formula
[tex]V_2 = \frac{C_1V_1}{C_2} [/tex]
where
C1 is the concentration of the stock solution
V1 is the volume of the stock solution
C2 is the concentration of the diluted solution
V2 is the volume of thevdiluted solution
From the question
C1 = 1.45 M
V1 = 25 mL
C2 = 0.0245 M
So we have
[tex]V_2 = \frac{1.45 \times 25}{0.0245} = \frac{36.25}{0.0245} \\ = 1479.59...[/tex]
We have the final answer as
1479.60 mLHope this helps you
Pb-214 in beta decay
Lead 214 emits then beta electrons to transform into bismuth 214 and polonium 214, which produces lead 210 through the emission of a third alpha particle. This series of transformations take place in a time span roughly equal to an hour.
Hope this helps, if I am right, brainliest? :))))
Which statement explains why carbon-14 dating cannot be used to date ancient rocks?
Carbon-14 decays at a varying rate.
Carbon-14 decays relatively quickly.
Carbon-14 can be used only to date the remains of organisms.
Carbon-14 has a half-life that is much longer than potassium.
Answer:
its, b
Explanation:
took the test on e2020
Carbon-14 dating cannot be used to date ancient rocks because:
B. Carbon-14 decays relatively quickly.
Carbon-14 dating:It is a method for tracking down the time of natural materials, like wood, in light of their substance of radioactive carbon. Also, it is a technique for estimating the time of natural matter by investigating its carbon content.
The decay takes place around 55,000 years i.e half the amount of the radioisotope present at any given time.
Thus, option B is correct.
Find more information about Radioactive decay here:
brainly.com/question/1236735
A ratio that compares the length and width of a garden is what type of model?
A. Physical
B. Conceptual
C. Computer
D. Mathematical
Answer:
D. Mathematical
Explanation:
what ahppens when you free lava?
Answer:
It will melt everything and if lava goes into water it will become rock.
Hope this helped you!
Explanation:
What is Avogadro's number?
the number of atoms in exactly 14.00 g of carbon-12
the number of atoms in a kilogram of any substance
the number of atoms, molecules, ions, formula units, or other particles in a mole of a substance
the number of atoms, molecules, ions, formula units, or other particles in a gram of a substance
Answer:
C
Explanation:
its not A since its actually the atoms in exactly 12g of crabon-12
-not B since its grams not kilograms
-not D since it says "gram" which would mean that we measure the particles in a gram instead of a mole
Avogadro's number is the number of atoms, molecules, ions, formula units, or other particles in a mole of a substance. Therefore, option (c) is correct.
What is Avogadro's number?The Avogadro constant commonly denoted [tex]N_A[/tex] is the proportionality factor that the number of constituent particles such as molecules, atoms, or ions in one mole of a sample.
Avogadro's number is a constant with an exact value of 6.022 × 10²³ reciprocal moles. Avogadro's number is named by Stanislao Cannizzaro after the Italian scientist Amedeo Avogadro, who explained it four years after Avogadro's death.
The numerical value of the Avogadro constant is in reciprocal moles, a dimensionless number known as the Avogadro number. The value of the Avogadro constant, the mass of one mole of a chemical compound, in grams.
It is numerically equal to the average mass of one molecule of the compound in daltons. One dalton is 1/12 of the mass of one carbon-12 atom, which is the mass of one nucleon.
Learn more about Avogadro's number, here:
https://brainly.com/question/1445383
#SPJ6
Can someone please help me with this? :(
Answer:
Bo
Explanation:
Bo is not a element
The nutrition label on rice lists the amounts of proteins, carbohydrates, and fats in one serving. These substances are important for human nutrition. How are proteins, carbohydrates, and fats related to the discipline of chemistry?
Answer:All are chemical compounds.
boling water is considered as
Answer:Boiling water is a physical change, as it rearranges molecules but does not affect the internal structures. Boiling water forces the water molecules away from each other as the liquid changes to vapor. In a chemical change, new chemical substances are created or formed. Advertisement. Physical changes affect the state of an item, and a chemical change happens at a molecular level.
Explanation:
hope it helps:))
Answer:
gragsgv
Explanation:
cwnbcsjhbvcd
What mass of neon gas is required to fill a 5.00-L container to
a pressure of 1.02 atm at 25 °C?
Answer:
[tex]m=4.21g[/tex]
Explanation:
Hello,
In this case, by using the ideal gas equation:
[tex]PV=nRT[/tex]
We can compute the mass of neon gas at the given conditions by firstly computing the moles and also considering the temperature in kelvins (298K):
[tex]n=\frac{PV}{RT}=\frac{1.02atm*5.00L}{0.082\frac{atm*L}{mol*K}*298K}\\ \\n=0.209mol[/tex]
Finally, by using the atomic mass of neon gas (20.18g/mol) we compute the required mass to fill the 5.00-L container:
[tex]m=0.209mol*\frac{20.18g}{1mol}\\ \\m=4.21g[/tex]
Best regards.
The mass of neon gas will be "4.21 g".
Ideal Gas Equation:Given:
Pressure, P = 1.02 atmVolume, V = 5.00 LTemperature, T = 25°C or 298 KBy using Ideal Gas Equation,
⇒ [tex]PV = nRT[/tex]
or,
⇒ [tex]n = \frac{PV}{RT}[/tex]
By substituting the values,
[tex]= \frac{1.02\times 5.00}{0.082\times 298}[/tex]
[tex]= 0.209 \ mol[/tex]
hence,
The Mass will be:
= [tex]0.209\times \frac{20.18}{1}[/tex]
= [tex]4.21 \ g[/tex]
Thus the above answer is right.
Find out more information about ideal gas equation here:
https://brainly.com/question/4147359
How many sig figs are in 340.0 mL
Answer:
4
Explanation:
there is a decimal place present. so you would take away any zeros before the number.
Answer:
4 i think
Explanation:
Describe each highlighted bond in terms of the overlap of atomic orbitals. (If the highlighted bond is not a pi bond, select the blank option from the dropdown menu.) Compound 1: Molecular orbital type: _________ Atomic orbitals in the sigma bond: _________ Atomic orbitals in the pi bond: _________ Compound 2: Molecular orbital type: _________ Atomic orbitals in the sigma bond: _________ Atomic orbitals in the pi bond: _________
The image of the bonds are missing, so i have attached it.
Answer:
A) - Sigma bond
-Sp³ and Sp³
- None
B) - Sigma and pi bond
- Sp² of C and p of O
- p of C and P of O
Explanation:
A) For compound 1;
- the molecular orbital type is sigma bond due to the end-to-end overlapping.
- Atomic orbitals in the sigma bond will be Sp³ and Sp³
- Atomic orbitals in the pi bond would be nil because there is no pi bond.
B) For compound 2;
- the molecular orbital type is sigma and pi bond
-Atomic orbitals in the sigma bond would be Sp² of C and p of O
- The Atomic orbitals in the pi bond will be; p of C and p of O
How many neutrons are there in 8 molecules of
[tex] \frac{19}{9} f2[/tex]
Answer:
128 neutrons
Explanation:
How many neutrons are there in 8 molecules of [tex]^{19} _9 F_2[/tex]?
Step 1: Calculate the number of neutrons in 1 atom of F.
The atomic number (z) of F is 9 and its mass number (A) is 19. We can calculate the number of neutrons using the following expression.
n⁰ = A - Z = 19 - 9 = 10
Step 2: Calculate the number of neutrons in 1 molecule of F₂.
1 molecule of F₂ contains 2 atoms of F. The number of neutrons in 1 molecule of F₂ is:
(8 n⁰/1 atom F) × (2 atom F/1 molecule F₂) = 16 n⁰/1 molecule F₂
Step 3: Calculate the number of neutrons in 8 molecules of F₂
8 molecule F₂ × 16 n⁰/1 molecule F₂ = 128 n⁰
The compound 2-hydroxybiphenyl (o-phenylphenol) boils at 286 °C under 101.325 kPa and at 145 °C under a reduced pressure of
14 Torr. Calculate the value of the molar enthalpy of vaporization. Compare this value to that given in the CRC Handbook.
Answer: [tex]\Delta H_{vap}[/tex] = 55.1 kJ/mol
Explanation: Molar Enthalpy of Vaporization([tex]\Delta H_{vap}[/tex] ) is the energy needed to change 1 mol of a substance from liquid to gas at constant temperature and pressure.
For the 2-hydroxybiphenyl, there two temperatures and 2 pressures. In this case, use Clausius-Clapeyron equation:
[tex]ln\frac{P_{2}}{P_{1}}=\frac{\Delta H_{vap}}{R} (\frac{1}{T_{1}}-\frac{1}{T_{2}} )[/tex]
[tex]\Delta H_{vap}[/tex] is in J/mol:
1) Temperature in K
[tex]T_{1}=[/tex] 286 +273 = 559K
[tex]T_{2}[/tex] = 145 + 273 = 418K
2) Both pressure in Pa
[tex]P_{1}[/tex] = 101325Pa
[tex]P_{2}[/tex] = 14*133 = 1862Pa
Since molar enthalpy is in Joules, gas constant R is 8.3145J/mol.K
Replacing into the equation:
[tex]ln\frac{1862}{101325}}=\frac{\Delta H_{vap}}{8.3145} (\frac{1}{559}-\frac{1}{418} )[/tex]
[tex]ln(0.0184)=\frac{\Delta H_{vap}}{8.3145} (\frac{141}{233662} )[/tex]
[tex]\Delta H_{vap}=\frac{-3.9954*1942782.7}{-141}[/tex]
[tex]\Delta H_{vap}=55051.02[/tex]
[tex]\Delta H_{vap}=55051.02[/tex]
[tex]\Delta H_{vap}=55.1[/tex] kJ/mol
Using those values, molar enthalpy is 55.1 kJ/mol
Comparing to the CRC Handbook, which is [tex]\Delta H_{vap}=71[/tex] kJ/mol:
[tex]\frac{55.1}{71}[/tex] = 0.78
The calculated value is 0.78 times less than the CRC Handbook.
An atomic model shows 19 protons, 20 neutrons, and 19 electrons. What is the mass number of the atom?
A substance made up of one type of atom is called an(a) ______________.
A. element
B. compound
C. atom
A substance that cannot be converted into another substance is known as an element. Each type of atom that makes up an element is unique. The correct option is A.
A substance whose atoms all contain the same number of protons is said to constitute an element; alternatively, all the atoms of a certain element must contain the same number of protons. Chemical reactions cannot degrade elements since they are the simplest chemical forms.
A compound is created when two or more components join chemically in a predetermined mass ratio.
Thus the correct option is A.
To know more about elements, visit;
https://brainly.com/question/29545466
#SPJ6
What does a cell nucleus do?
Select one:
a. control everything the cell does
b. surround the cell
c. hold important chemicals the cell needs
d. protect the cell.
Answer:
a. control everything the cell does
Explanation:
the nucleus is like the brain of the cell
(b) Draw the structure of the products when cyclopentene is reacted with:
(i) Cold alkaline KMnO4
Answer:
See explanation and image attached
Explanation:
When an alkene is reacted with cold, dilute and alkaline KMnO4, the product of the reaction is a 1,2-diol (vicinal diol). The products exhibit a “syn” stereochemistry with the addition of the two -OH groups to the same side of the alkene.
The reaction of cyclopentene with cold, dilute, alkaline KMnO4 is shown in the image attached.
In the given query, when cyclopentene is reacted with cold alkaline [tex]\rm KMnO_4[/tex], the product formed is cis-1,2-cyclopentanedicarboxylic acid (image attached below).
The reaction proceeds via oxidative cleavage of the double bond in cyclopentene to form two carboxylic acid groups.
The potassium permanganate ([tex]\rm KMnO_4[/tex]) acts as a strong oxidizing agent and cleaves the double bond to form two carboxylic acid groups.
The reaction can be represented as follows:
Cyclopentene + cold alkaline [tex]\rm KMnO_4 \rightarrow[/tex] cis-1,2-cyclopentanedicarboxylic acid
Therefore, the product, cis-1,2-cyclopentanedicarboxylic acid (refer to the attached image below), has a cyclopentane ring with two carboxylic acid groups attached to the 1 and 2 carbons, respectively.
Learn more about reaction here:
https://brainly.com/question/28546817
#SPJ3
A average marathon runner run the 26.1 miles in 4 hrs 30 minutes. What is the runners average pace in miles/minutes.
Explanation:
4hr 30 m = 270 min
270/ 26.1 = 10. 34
1 mile per 10.34 mins
A runner averages 8 minutes and 25 seconds per mile. What is her average velocity in miles per hour?
8 minutes and 25 seconds is the same as 8.25 in decimal form.
Divide by 60 minutes.
60 / 8.25 = 7.27 miles per hour
Best of Luck!