Answer:
Option B: Oxygen.
Explanation:
Hope this helped.
An electron in the n=7 level of the hydrogen atom relaxes to a lower energy level, emitting light of 93.1 nm.
What is the value of n for the level to which the electron relaxed?
answer:
nf=2
Explanation:
It is given that,
Initially, the electron is in n = 7 energy level. When it relaxes to a lower energy level, emitting light of 397 nm. We need to find the value of n for the level to which the electron relaxed. It can be calculate using the formula as :
why is water a clear liquid?
A solution contains 5.2 moles of NaCl in 0.5 L of water. What is the molarity of this solution? (Show your work)
Answer:
10.4 M
Explanation:
5.2 Moles / .5 L = 10.4 M
In your own words, define the following terms.
star
Answer:
A Sun that is hot and big and sparkling
Explanation:
A Star is a Sun which is tended to be true
Answer:
A star is a miniature version of a sun, which burns out over a course of time.
For a reaction where ∆H° = +573 kJ/mol and ∆S° = +1.64 kJ/mol･K, at what temperature, in K, does X(l) → X(g) occur spontaneously?
The temperature in kelvin (K) in which the reaction occurs spontaneously is given as 349 K
What is entropy?Entropy is simply defined as the measure of the degree of the disorderliness of a system. Mathematically, it can be expressed as:
ΔS = ΔH / T
Where
ΔS is the change in entropy of system ΔH is the enthalpy change T is the temperature How to determine the temperature Enthalpy change (ΔH) = +573 KJ/molChange in entropy (ΔS = +1.64 KJ/mol･K Temperature (T) =?ΔS = ΔH / T
1.64 = 573 m T
Cross multiply
1.64 × T = 573
Divide both side by 1.64
T = 573 / 1.64
T = 349 K
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During which lunar phase would you observe the highest tides?
A) Phase 1
B) Phase 2
C) Phase 3
D) Phase 4
Answer:
3
Explanation:
This is the answer because when it is full moon the tides are higher.
Of the following elements, which has the lowest electronegativity?
Br
Cl
Ca
Mg
what is the volume occupied by 6.8gm of H2S at STP (at mass H=1,S=32)
The volume occupied by 17g of H2S at s.t.p. is [H = 1.00, S = 32.0, Molar volume = 22.4 dm3]
Options
A) 11.2dm 3
Kelly's spring scale indicates that it takes 4.9 newtons of force to lift the mass directly.
With the lever, she plans to add masses to the right side until it is able to lift the 500-gram mass 10 cm.
Consider the location of the lever's fulcrum. When Kelly has added enough mass to the right side, she should expect the downward force exerted on the right side of the lever to be
A.
equal to 500 grams.
B.
less than 4.9 newtons.
C.
equal to 4.9 newtons.
D.
greater than 4.9 newtons.
Answer:
less than 4.9 newtons Explanation:
Name the alkyne. Spelling and punctuation count.
CH
C
H3C-CH2-CH2-CH-CH2-CH2-CH2-CH3
Answer:
[tex] \boxed{ \sf \: 3-propyl-hept-1-yne}[/tex]
Explanation:
To know the name of Alkyne, use IUPAC(International Union of Pure and Applied Chemistry).
According to IUPAC, for the naming of any organic compound containing a triple bond, find the longest chain that contains triple bond & number the chain from the side where triple bond gets lowest number.
in the above diagram, the parent chain cobtains seven carbon atoms with a propyl substituent at 3rd carbon atom. during naming of the compound mention the substituent first along with the position of carbon where is it. Now 7 carbon Atom have prefix (-hept) and Alkyne group is on the first position hence the parent chain would be (hept-1-yne) and substituent (3-propyl).
hence the name of compound is 3-propyl-hept-1-yne
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The cylinder of a car's engine has a volume of 0.6250 L when the piston is at the bottom of the cylinder. When the piston is at the top of the cylinder the volume is 0.0600 L. If the cylinder is filled with air at an atmospheric pressure of 765.1 mm Hg the piston is at the bottom, what is the pressure in units of kPa when the piston is at the top of the cylinder?
The new pressure in the cylinder of the car engine as the piston is moved to the top is 1062.55kPa
Boyle's lawBoyle's law states that "volume of a given quantity of gas is inversely proportional to its pressure as long as temperature remains constant.
It is expressed as;
P₁V₁ = P₂V₂
Given the data in the question;
Initial volume V₁ = 0.6250LNew volume V₂ = 0.0600LInitial pressure P₁ = 765.1mmHg = 1.0067107atmNew pressure P₂ = ?To determine the new pressure as the piston is at the top of the cylinder, we substitute our given values into the expression above.
P₁V₁ = P₂V₂
P₂ = P₁V₁ / V₂
P₂ = ( 1.0067107atm × 0.6250L ) / 0.0600L
P₂ = 0.629194188Latm / 0.0600L
P₂ = 10.4865698atm
P₂ = 1062.55kPa
Therefore, the new pressure in the cylinder of the car engine as the piston is moved to the top is 1062.55kPa
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Hey guys i needed some help on this
Based on the bond energies given, the standard enthalpy of the reaction, ΔH°(rxn) is -296 kJ.
What is standard enthalpy change of a reaction?The standard enthalpy change of a reaction is the energy changes involved when substances react under standard conditions to form products.
ΔH°(rxn) = sum of the bond energies of bonds being broken - sum of the bond energies of the bonds being formed.The standard enthalpy of the reaction, ΔH°(rxn) is calculated as follows:
Sum of energy of bonds broken = 839 + (2 × 413) + (432 × 2) = 2529 kJ
Sum of energy of bonds formed = 347 + (6 × 413) = 2825 kJ
ΔH°(rxn) = (2529 - 2825) kJ
ΔH°(rxn) = -296 kJ
Therefore, the standard enthalpy of the reaction, ΔH°(rxn) is -296 kJ.
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How many liters of nitrogen gas are needed if 15.9g of aluminum is produced?
please show work
Answer:
6.6 L ( if you wrote your Q correctly)
Explanation:
2 Al + 1 N2 = 2 Al N
Al mole weight = 26.981 gm
given 15.9 Al How many L of N2 are needed?
15.9 / 26.981 = .5893 moles of Al
we need 1/2 as many moles of N2 ( from the balanced equation above)
= .29465 moles of N2
22.4 L/ mole for STP gas = 6.6 L
What is ∆G° for a redox reaction where 6 moles of electrons are transferred and E° =-2.25 V? (F = 96,500 J/(V･mol))
A redox reaction with E° = -2.25 V involving the transference of 6 moles of electrons has a ΔG° of 9.38 × 10⁵ J.
What is the standard Gibbs free energy?The standard Gibbs free energy (ΔG°) is a thermodynamical function that indicates the spontaneity of a reaction.
A redox reaction, in which 6 moles of electrons are transferred (n = 6 mol), has a standard cell potential (E°) of -2.25 V.
Knowing that the Faraday's constant is F = 96,500 J/V.mol, we can calculate the standard Gibbs free energy using the following expression.
ΔG° = - n × F × E°
ΔG° = - 6 mol × (96,500 J/V.mol) × (-2.25 V) = 9.38 × 10⁵ J
A redox reaction with E° = -2.25 V involving the transference of 6 moles of electrons has a ΔG° of 9.38 × 10⁵ J.
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Name five renewable energy resources.
Answer:
Solar energy, geothermal energy. Wind energy. Hydropower, Biomass.
Explanation:
The equation above is not balanced. Balance the equation on a scratch sheet of paper. Match each letter to the correct coefficient that will balance the equation. Remember, if there is no coefficient, it is understood to be 1. Some numbers may be used more than once.
In order to balance the equation, A would be 1, B would be 3, C would be 1, and D would be 2 respectively.
Balancing chemical equationA balanced chemical equation has the same number of each of the component atoms at the reactant and product sides.
Thus, the balanced chemical equation for the reaction in the illustration would be:
[tex]CS_2 + 3O_2 --- > CO_2 + 2SO_2[/tex]
Thus:
A = 1B = 3C = 1D = 2More on balancing chemical equations can be found here: https://brainly.com/question/15052184
A solution is made by adding 15 g of sodium chloride into 150 g of water. What is the mass percentage of this sodium chloride in this solution?
Answer:
[tex]\sf \fbox {mass \:percentage \: = 9.09 \%}[/tex]
Explanation:
Given:
Mass of solute = 15g
Mass of solvent (Water)= 150g
To find:
Mass percentage of sodium chloride=?
Solution:
Let's find out the mass of overall solution first,
Mass of solution= Mass of solute+ mass of solvent
Mass of solution = 15+150= 165 gram
Now we know that,
[tex] \sf \: mass \:percentage \: = \frac{Mass \: of \: solute}{Mass of solution} \times 100 \\ \sf \: mass \:percentage \: = \frac{15}{165} \times 100 \\ \sf \: mass \:percentage \: = \frac{1500}{165} \\ \sf \fbox {mass \:percentage \: = 9.09 \%}[/tex]
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A balloon has a volume of 12.0 L at a pressure of 98.7. kPa. What will be the new volume when the pressure drops to 56.7 kPa?
Answer:
20.89 LITERS
Explanation:
P1V1=P2V2
P1V1 / P2 = V2
98.7 * 12/56.7 = 20.89 LITERS
The cell membrane is a flexible structure that surrounds both plant and animal cells. The arrangement of molecules within the cell membrane makes it semi-permeable. That is, the cell membrane allows some substances to easily diffuse into and out of the cell, but it prevents the diffusion of other substances.
Plant and animal cell diagram
The cell wall is a rigid structure that surrounds plant cells. The materials found in the cell wall protect the plant cells and give plants structural support.
Which conclusion can be made given the above information?
Answer:
The true answer is the Cell membrane and animal cells invisible
Explanation: nothing. eshh
Breathing is one of the most universal and habitual practices that humans do. Most of the time, we don't even think about it. Our lungs allow us to breathe in air and provide much needed oxygen to the rest of the body. It also eliminates carbon dioxide to get rid of this waste material of our body. This breathing process is made possible because of Boyle's law.
In at most 100- word essay, explain how Boyle's law applies to human breathing apparatus and suggest ways on how to take good care of our healthy lungs.
Answer:
lets Do it dude
We can breathe air in and out of our lungs because of Boyle’s law. According to Boyle’s law, if a given amount of gas has a constant temperature, increasing its volume decreases its pressure, and vice-versa.When you inhale, muscles increase the size of your thoracic (chest) cavity and expand your lungs. This increases their volume, so pressure inside the lungs decreases. As a result, outside air rushes into the lungs. That’s because a gas always flows from an area of higher to lower pressure.When you exhale, muscles decrease the size of your chest cavity and squeeze your lungs. This decreases their volume, so pressure inside the lungs increases. As a result, air rushes out of the lungs, flowing from an area of higher to lower pressure.Explanation:
Checkmate
A 16.0 g sample of methane gas, CH4, the gas used in a chemistry lab, has a volume of 5.0 L at 27ºC. Calculate the pressure.
Answer:
4.9 atm
Explanation:
convert 16.0g of CH4 to moles
16.0 g CH4 x 1 mol CH4/16.0 g CH4 = 1.00 mol of methane
convert the temp into Kelvins: 27 + 273 = 300.K
PV = nRT
(P) (5.0 L) = (1.00 mol) (0.0821 L atm/mol K) (300.K)
P = 4.9 atm
Put the appropriate processes to their respective bins
Answer:
Remember
Endo = To EnterExo = To ExitThermic = HeatA sparkler burning is an exothermic reaction
Sparkler burning is an exothermic reaction and so the sign of the ΔH must be negative (–∆H) indicating that heat was released.
Ice melting is an endothermic reaction (+∆H) because the ice absorbs (heat) energy, which causes a change to occur.
Acetone evaporating from skin is an endothermic reaction (+∆H). Because, molecules that are evaporating are absorbing heat. So, evaporation is called endothermic.
Could someone please tell me the name of this branched alkane?
Answer:
2-Methylhexane
Explanation:
A 1 kg block of iron sits outside in the direct sun from 8am to 10am. At 8am the temperature of the block was 20.0°C and at 10am the temperature of the block was 27.5°C.
How much heat did the block of Iron absorb from the sun?
use q=mcΔT
Answer:
About 3.5 kJ.
Explanation:
Recall the heat transfer equation:
[tex]\displaystyle q = mC\Delta T[/tex]
Where q is the heat; m is the mass of the substance; C is its specific heat; and ΔT is the change in temperature.
The given specific heat of iron is 462 J/kg -°C.
Substitute and evaluate. Ensure correct units:
[tex]\displaystyle \begin{aligned} q & = (1\text{ kg})\left(\frac{462\text{ J}}{\text{kg -$^\circ$C}}\right)(27.5\text{ $^\circ$C} - 20.0\text{ $^\circ$C}) \\ \\ & = (1\text{ kg})\left(\frac{462\text{ J}}{\text{kg -$^\circ$C}}\right)(7.5\text{ $^\circ$C}) \\ \\ & = 3.5\times 10^3 \text{ J} = 3.5\text{ kJ}\end{aligned}[/tex]
Therefore, the block of iron absorbed about 3.5 kJ of heat.
So
Q=mc∆TQ=1(462)(7.5)Q=3500JThe block absorbed 3500J of heat
Can you light diamond on fire?
Answer:
Because diamond is comprised of carbon, it may be set on fire and even burned.
Explanation:
Why cuz diamonds are made out of carbon
Answer:
Why cuz diamonds are made out of carbon
Explanation:
If the Ksp of NaCl is experimentally determined to be 53.9, then what is the concentration of Na (in M) when it begins to crystallize out of solution
For the concentration of Na in M when it begins to crystallize out of the solution is mathematically given as
Na+ = 0.125M
what is the concentration of Na in M when it begins to crystallize out of the solution?Generally, the equation for the Ksp of the solution is mathematically given as
Na⁺+CL⁻
Ksp = SxS
53.9 = s^2
S = 7.34
Molar mass Nacl 58,44
Solubility = 7.34/58.44
Solubility = 0.125M
In conclusion, the concentration of Na in M when it begins to crystallize out of the solution
Na+ = 0.125M
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A glass tube contains mercury. What would be the height of the column of mercury which would create pressure equal to 1.00 atm
Since 1.00 atm is equal to 760 mmHg, the height of the column of mercury which would create pressure equal to 1.00 atm is 760 mm or 76 cm
What are the units of pressure?Pressure is defined as the force acting perpendicularly per unit area of a surface.
The units of pressure include;
millimetres of mercury, mmHgaatmospheres, atm,pascals, PaNewtons per square metre, N/m^21 atmosphere is equal to 760 mmHg.
Therefore, the height of the column of mercury which would create pressure equal to 1.00 atm is 760 mm or 76 cm
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Below is the thermochemical equation for the combustion of octane.
How much heat is released during the combustion of 8 moles of octane (C8H18)
Question 4 options:
Impossible to answer this question with the information provided.
43,764 kilo joules of heat is released
7,004,224 kilo joules of heat is released
2735 kilo joules of heat is released
87,528 kilo joules of heat is released
from equation 2 moles = - 10,941 kJ
for 8 moles:
8/2 x -10,941 = -43,764 kJ
-43,764 kJ heat is released during the combustion of 8 moles of octane.
How to find the amount of heat released?To calculate the amount of heat released in a chemical reaction, use the equation Q = mc ΔT, where Q is the heat energy transferred (in joules), m is the mass of the liquid being heated (in kilograms), c is the specific heat capacity of the liquid (joule per kilogram degrees Celsius), and ΔT is the change in temperature.
from equation 2 moles = - 10,941 kJ
for 8 moles:
8/2 x -10,941 = -43,764 kJ
When octane is burned, carbon dioxide gas is generated, as shown in the reaction equation. This is typical of hydrocarbon combustion reactions, such as octane and propane.
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Marie had to wait at the railroad tracks from a train to pass. How long did she wait?
Answer:
she waited 30 minutes
Explanation:
i need brain liest
why is it important for scientist to be objective when using the design process like the scientific method when doing their investigations
Answer:
your mom
Explanation:
grandma + grandpa = mom