Answer:
right answer is option no c
What is the reason for the emission of light after the gas in a discharge tube is excited?
A)
photo-electric emission
Eliminate
B)
spontaneous radioactive reaction
C)
energy jumps by electrons due to excitation
D)
high energy reaction of the gas inside the tube
Answer:
c
Explanation:
took test on usa testprep
When gas in a discharge tube is excited to higher energy level after some seconds they return to the ground level by releasing energy in the form of light. Thus energy jumps by electron due to excitation is correct option.
What is gas discharge tube?A gas discharge tube is an electronic devise containing inert gases that ionizes and conducts results in emission of light.
When a potential is applied between the electrodes in a gas discharge tube, and the pressure is reduced, the gas particles inside forms a plasma of ions.
The electrons released when excited to higher energy level by absorbing energy and returns to the initial state by emitting energy in the form of light, the discharge tube glows.
The color emitted by the discharge tube vary based on the gas in the tube. Each type of gaseous ions emit different colors.
Therefore, the light emission in gas discharge tube is due to energy hike during electron excitation and then relaxing by emitting the light energy. Thus, option c is correct.
To find more about gas-discharge tube, refer the link below:
https://brainly.com/question/5468708
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HELP I WILL MARK YOU AS THE BRAINLIEST ANSWER
The atomic radii of elements on the periodic table generally _______ from left to right and _______ from top to bottom.
A.
increase; decrease
B.
decrease; increase
C.
stay the same; increase
D.
increase; increase
Hey there! Here is the answer:
B.) decrease; increase
Here's why:
As you move from left to right across a period on the periodic table the size of an atom will decrease. As you move from top to bottom down a group on the periodic table the size of an atom will increase.
I really hope this answer helps you out! :)
Solid calcium oxide and gaseous water are produced by the decomposition of solid calcium oxide hydroxide. Write a balanced chemical equation for this reaction.
[tex]\boxed{\sf {Ca(OH)_2(s)\atop Calcium\:Hydroxide}\longrightarrow {CaO(s)\atop Calcium\;oxide}+{H_2O(g)\atop water}}[/tex]
On reactant side
Hydrogen= 2atomsOxygen=2atomsCalcium=1atomOn product side
Hydrogen=Oxygen=2atomsCalcium=1atom.hence balanced.
A rabbit has a mass of 2kg. What is its weight
Answer:
weight = Mass × gravity
P= m × g
P=mg
Weight (P) = ? , Mass (m) = 2 kg , gravity (g) = 9.8 m/s²
P= mg
p = 2 × 9.8
P= 19.6 kg.m/s²
P= 19.6 N
I hope I helped you^_^
heterogeneous mixture homogeneous
How are they similar?
Answer:
By definition, a pure substance or a homogeneous mixture consists of a single phase. A heterogeneous mixture consists of two or more phases. When oil and water are combined, they do not mix evenly, but instead form two separate layers. Each of the layers is called a phase.
Explanation:
As discussed during the lecture, the enzyme HIV-1 reverse transcriptae (HIV-RT) plays a significant role for the HIV virus and is an important drug target. Assume a concentration [E] of 2.00 µM (i.e. 2.00 x 10-6 mol/l) for HIV-RT. Two potential drug molecules, D1 and D2, were identified, which form stable complexes with the HIV-RT.
The dissociation constant of the complex ED1 formed by HIV-RT and the drug D1 is 1.00 nM (i.e. 1.00 x 10-9 mol/l). The dissociation constant of the complex ED2 formed by HIV-RT and the drug D2 is 100 nM (i.e. 1.00 x 10-7 mol/l).
1. Compute the total concentration of [D1]tot that is needed to bind 90% of the HIV-RT at the given concentration [E]tot. Provide your answer as a numerical expression with 3 significant figures in the unit mol/l. You do NOT have to consider competition betwwen the drugs D1 and D2! They are administered separately.
2. Compute the total concentration of [D2]tot that is needed to bind 90% of the HIV-RT at the given concentration [E]tot. Provide your answer as a numerical expression with 3 significant figures in the unit mol/l.You do NOT have to consider competition betwwen the drugs D1 and D2! They are administered separately.
Answer:
C)[D]/[ED] = 5.20
D)[D]/[ED] = 5.20
E)[D']_T = 1.495* 10 ^-7 M
F)[D'] / [ED'] = 0.0579
Explanation:
E = 250 nM =2.5* 10 ^-7 mol/L , T=298.15 K
Dissociation constant of K_D = 1.3 μM (1.3 *10 ^-6 M)
E + D ⇄ ED → K_a = [ED] / [D][E] (association constant)
ED ⇄ E + D → K_D = [E][D] / [ED] (dissociation constant)
C)
[E] =2.5*10^-7 mol/L
K_D = 1.3* 10^-6 M
K_D = [E][D] / [ED] → [D]/[ED] = K_D / [E]
= [D]/[ED] = 1.3* 10 ^-6 / 2.5 *10^-7
= 13/25 * 10
=130/25 = 5.20
[D]/[ED] = 5.20
D)
ΔG =RTln Kd
ΔG_2 for E and D = 1.987 * 298.15 * ln 1.3*10^-6
ΔG_2 592.454 * [ln 1.3 +ln 10^-6]
ΔG_1 = 592.424 [0.2623 - 13.8155]
ΔG_2 = -592.424 * 13.553
ΔG_1 = -8184.633 cal/ mol
ΔG_1 = -8184.633 * 4.18 J/mol = -34244.508 J?mol
ΔG_1 = -34.245 KL/mol
so, ΔG_2 = ΔG_1 - 10.5 KJ/mol
ΔG_2 = -34.245 - 10.5
ΔG_2 = -44.745KJ / mol
ΔG_2 =RT ln K_D
-44.745 *10^3
=8.314 *298.15 lnK_D
lnK_D' = - 44745 / 2478.81 g
ln K_D' = -18.051
K_D' = -18.051
K_D' = e^-18.051
[D]/[ED] = 5.20
E)
[E] = 2.5* 10 ^-7 mol/ L = a
K_D' = [E][D] / [ED'] E +D' → ED'
K_D' = a/2(x-(a/2) / (a/2)
KD' = x - a/2
=2.447 *10^-8 = (2.5/2) * 10^-7
x=2.447 * 10^-8 + 1.25 * 10^-7
x = 2.447 *10^-8 + 1.25 * 10 ^-7
x= 10^-7 [1.25 + 0.2447]
x = 1.4947 * 10^-7
[D']_T = 1.495* 10 ^-7 M
F)
K_D' = [E][D'] / [ED']
[D'] / [ED'] = KD' / [E]
[D'] / [ED'] = 1.447 *10^-8 / 2.5* 10^-7
[D'] / [ED'] = 0.5788 * 10^-1
[D'] / [ED'] = 0.0579
Explanation:
...
Ammonium carbonate solution is added to dilute nitric acid. What is the balanced chemical equation?
Which of the following are considered elements:
Answer:
considered as element
Helium He
1. Distinguish between a mixture and a pure substance.
Answer:
1)Mixture is the combination of substance
2)There are two types of mixture such as heterogeneous mixture and homogeneous mixture
3)foreg=Salt solution ,sedimentation
Pure substance
1)Pure substances are also called elements
2)They are made up of small atoms
3)for eg= oxygen,Venadium ,Iron,Oxygen
6. How many meters are in 0.00253 kilometers?
Answer:
2.53 kilometers
Answer
Choice A
Answer
Choice B
Answer
Choice C
Question
A scientist hypothesizes that a new medication can reduce
the chances of catching a cold Which of these would most
likely be the dependent variable in a study involving this
medication?
//
The participants
who do not receive
the medication
Color PURPLE
The number of
participants who
catch a cold
Color YELLOW
The age of the
participants
Color GRAY
Tt remains the
T+ is purposely
It is used for
Answer:
what is the question????
Hehe someone help I have put down heat but I think there is another
Answer:
chemical potential enery
Mark brainliest
Describe what must be happening to the particles above as the change is happening
Answer:
d
Explanation:
solids the modicual are tightly packed
liquid, more room to move around aka not so tightly packed
gas, can move where ever it wants aka not paked at all
HELP! 100 points if you give a valid answer and brainliest if it's detailed!
Explanation:
The extract of plant is not done in fixed proportion
it is heterogeneous
When you wash your hands or dishes, you probably don't use just water. In 5-7 sentences, explain what
you use to help you wash up, how it works, and why you think it works.
Hello! here is a paragraph you can use, that I type up to explain, make sure to not copy word for word of what I said. :)
What I use to wash up is soap. Soap has a certain ph level and includes acids and alkaline that enables water to mix and create soap foam to clean. Soap can come in many shapes and sizes, and can be either liquid, solid, or even foamy. I think soap works because when you use friction between your wet hands and the soap bar, you are rubbing the substances of the soap that clean your hands to clean your hands. I think the friction of the rubbing creates a layer of soap that can be used to clean, and when you increase friction the more change of the soap.
Have a great day,
I hope this helps!
This picture shows students working in a
chemistry laboratory. What could they do to make
their lab safer?
Label the test tubes and plastic cups.
Move the fire extinguisher closer to their
table.
Wear chemical protective gloves.
Reduce the clutter on the table.
Stand at the table instead of sitting. Tie long hair back.
DONE
Answer:
yes it is true they apply necessary safety measures
Answer: Label the test tubes, wear chemical protective gloves, tie long hair back
Explanation:
Just got it wrong
A popular car has a gas tank that holds a maximum of 14.5 gallons of fuel. What is
the size of the tank in liters ?
Answer:
54.883, so rougly about 54.9 liters.
Explanation:
To convert gallons to liters, multiply the amount of gallons by 3.785.
14.5 * 3.785 = 54.883
Taking into account the change of units, the size of the tank is 54.88 liters.
In first place, the rule of three is a tool used to quickly solve problems involving a proportional relationship between two variables.
The rule of three is a way of solving problems of proportionality between three known values and an unknown value, establishing a relationship of proportionality between all of them.
If the relationship between the magnitudes is direct, that is, when one magnitude increases, so does the other (or when one magnitude decreases, so does the other), the direct rule of three should be applied.
The rule of three is applied as follows, with A, B and C being known values and D being an unknown value: if A maintains a certain relationship with B, and it is known that C and D have the same relationship, it is possible to calculate the unknown value D using the following expression:
[tex]D=\frac{CxB}{A}[/tex]
In this case, the rule of three can be applied as follows: if 1 gallon is equal to 3.785 liters, 14.5 gallons are equal to how many liters?
[tex]D=\frac{14.5 gallonsx3.785 liters}{1 gallon}[/tex]
Solving:
D= 54.88 liters
In summary, the size of the tank is 54.88 liters.
Learn more with this example:
https://brainly.com/question/17839792?referrer=searchResultshttps://brainly.com/question/14586541?referrer=searchResultswhich term best describes the role of hydrogen gas in the formation of a water molecule
A 0.450 M solution of HCl is prepared by adding some 1.50 M HCl to a 500 mL volumetric flask and diluting to the mark with deionized water. What volume of 1.50 M HCl must be added
Answer:
150 mL of 1.50 M HCL
Explanation:
So the equation you need to solve this equation is:
M1*V1=M2*V2 --> M1= Molarity of the acid you are diluting V1= Volume of the solution you need to dilute. M2=The molarity of thee solution you have made. V2=Volume of the solution you have made
M1= 1.50 M HCL
V1= Unknown
M2=0.450 M HCL
V2= 500 mL
Simple algebra says that V1= (1.5*500)/.450 = 150 mL of 1.50 M HCL
What causes the pressure in a gas
Answer:
Gas pressure is caused when gas particles hit the walls of their container. The more often the particles hit the walls, and the faster they are moving when they do this, the higher the pressure. This is why the pressure in a tyre or balloon goes up when more air is pumped in.
When 47.1 J of heat is added to 14.0 g of a liquid, its temperature rises by 1.80 ∘C. What is the heat capacity of the liquid?
Answer:
[tex]\boxed {\boxed {\sf 1.87 \J/g \textdegree C}}[/tex]
Explanation:
We are asked to find the specific heat capacity of a liquid. We are given the heat added, the mass, and the change in temperature, so we will use the following formula.
[tex]q= mc\Delta T[/tex]
The heat added (q) is 47.1 Joules. The mass (m) of the liquid is 14.0 grams. The specific heat (c) is unknown. The change in temperature (ΔT) is 1.80 °C.
q= 47.1 J m= 14.0 g ΔT= 1.80 °CSubstitute these values into the formula.
[tex]47.1 \ J = (14.0 \ g) * c * (1.80 \textdegree C)[/tex]
Multiply the 2 numbers in parentheses on the right side of the equation.
[tex]47.1 \ J = (14.0 \ g * 1.80 \textdegree C)*c[/tex]
[tex]47.1 \ J = (25.2 \ g*\textdegree C) *c[/tex]
We are solving for the heat capacity of the liquid, so we must isolate the variable c. It is being multiplied by 25.2 grams * degrees Celsius. The inverse operation of multiplication is division, so we divide both sides of the equation by (25.2 g * °C).
[tex]\frac {47.1 \ J}{(25.2 g *\textdegree C)} = \frac {(25.2 g *\textdegree C)*c}{{(25.2 g *\textdegree C)}}[/tex]
[tex]\frac {47.1 \ J}{(25.2 g *\textdegree C)} =c[/tex]
[tex]1.869047619 \ J/g *\textdegree C = c[/tex]
The original measurements of heat, mass, and temperature all have 3 significant figures, so our answer must have the same. For the number we found that is the hundredth place. The 9 in the thousandth place to the right tells us to round the 6 up to a 7.
[tex]1.87 \ J/ g * \textdegree C =c[/tex]
The heat capacity of the liquid is approximately 1.87 J/g°C.
89. The element bromine at room temperature is a liquid with a
density of 3.12 g/mL. Calculate the mass of 125 mL of bro-
mine. What volume does 85.0 g of bromine occupy?
The mass of 125 mL of bromine and the volume occupied by 85 g of bromine are:
1. The mass of bromine is 390 g. 2. The volume of bromine is 27.24 mL.Density is simply defined as the mass of an object per unit volume of the object. It can be expressed mathematically as
[tex]Density = \frac{mass}{volume }[/tex]
1. Determination of the mass of bromineDensity = 3.12 g/mL
Volume = 125 mL
Mass =?[tex]Density = \frac{mass}{volume} \\\\3.12 = \frac{mass}{125}[/tex]
Cross multiply
Mass = 3.12 × 125
Mass = 390 gTherefore, the mass of bromine is 390 g
2. Determination of the volume of bromineDensity = 3.12 g/mL
Mass = 85 g
Volume =?[tex]Density = \frac{mass}{volume } \\\\3.12 = \frac{85}{volume }[/tex]
Cross multiply
3.12 × Volume = 85
Divide both side by 3.12
[tex]Volume = \frac{85}{3.12}\\\\[/tex]
Volume = 27.24 mLTherefore, the Volume of bromine is 27.24 mL
Learn more: https://brainly.com/question/24460125
What is an atomic number
Answer:
the number of protons is called the atomic number
hope it helps you buddy
Answer: number of protons in an atom
Explanation:
what's the basic oxide
Answer:
Basic oxides are oxides that show basic properties in opposition to acidic oxides and that either react with water to form a base; or react with an acid to form a salt and water which are called neutralization reactions.
Explanation:
Mark me as brainiliest
Explanation:
A basic oxide is an oxide that shows basic properties in opposition to acidic oxides and that either ⁕reacts with water to form a base; or ⁕reacts with an acid to form a salt.
Arrange the following aqueous solutions in order of increasing boiling points.
0.050 m Mg(NO 3) 2; 0.100 m ethanol; 0.090 m NaCl
a. Mg(NO3) < NaCl < ethanol
b. ethanol < Mg(NO3)2 < NaCl
c. ethanol < NaCl < Mg(NO3)2
d. NaCl < ethanol < Mg(NO3)2
e. Mg(NO3)2 < ethanol < NaCl
Answer:
The correct choice is option b. ethanol < Mg(NO3)2 < NaCl
Explanation:
Ethanol = 0.100 m
Mg(NO3)2 = 0.15 m
NaCl = 0.18 m
The molar concentration of NaCl is the highest, which is why its boiling point will be the highest, too.
How many decigrams (dg) are in 0.779 kg?
Answer:
7790
Explanation:
Answer:
7790 decigrams
Explanation:
To scientific notation 5.029m
Answer:
5.029 × 100
Explanation:
13. Find the total number of atoms present in the following molecules.
a. 5 H₂O
b. Zn Cl₂
Answer:
zxcdfzdg
Explanation:
zszghzd
If you change the number of neutrons in an atom, you will also change its -
charge
element.
o
number
d
isotope.
Using the ruler, what is the value of A considering significant
figures?
Answer:
13.7 cm
Explanation:
If the number is between two whole numbers then that means it is going to be a decimal, how to determine the decimal is by how many ticks/lines are between it, so if you count from 13 cm and count each line as 1 you get to the number 7 and since that number is between the whole number it becomes 13.7
