Answer:
The most important elements that we use in everyday life include carbon, hydrogen, oxygen, with smaller amounts of things like chlorine, sulfur, calcium, iron, phosphorus,nitrogen, sodium, and potassium. Apart from these, other elements include magnesium, zinc, neon, and helium are also in our daily existence.
all these element are my favourite element .......
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^_^
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.
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what starting material with these reagents iwll result in this product 1.nanh2 2.ch3ch2br 3.h2, lindlar's cat.
Explanati la materia el convino
es carbón ya irogno
ed
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
how many grams are in one mole of CH3CO2H ?
Answer: 60.2g
Explanation:
One mole acetic acid weighs 60.2g
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!
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
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Please help ASAP!!!!!!!!
Answer:
the correct answer is option B batteries use chemicals to store energy
We have that the statement that remains true about batteries is
"Batteries use chemical to store energy "
Option B
-All battery are able to be recharged that is not correct as some batteries are non rechargeable
-A battery is a device composed of petrochemical cells, that rel sole upon the energy from chemical reactions to give off charge
-A battery is a device that is use to store energy. Therefore Batteries to not conserve energy
Hence the statement that remains true about batteries is
"Batteries use chemical to store energy "
Option B
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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????
Why is it important to use chemicals of high quality (purity) and exact(correct) concentrations in experiments?
Answer:
To produce good or targeted result
It is important to use chemicals of high quality and correct concentrations in experiment so that we can obtain the predictable result in an experiment
Purity of substances/chemicals is very important when performing experiments in the laboratories, because it plays an important role in the determination of the chemical properties of substances which will have a direct effect on the result obtained from the experiment. likewise using the correct concentration of reagents
During experiments to obtain the best/predictable result in an experiment it is of best practice to make use of chemicals of high quality and also at the exact(needed) concentrations, that way the predictable result of the experiment will be obtained.
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what is a characteristic of matter that allows it to change to something new? THE CORRECT ANSWER GETS BRAINLIEST!!!!
Answer:
a chemical property
Explanation:
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
13. Find the total number of atoms present in the following molecules. a. 5 H₂O b. Zn Cl₂
Answer:
A= 15 atoms B= 3
Explanation:
5 x 2 + 5 x 1
3 + 2 x 1
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! :)
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:
To scientific notation 5.029m
Answer:
5.029 × 100
Explanation:
Give reasons ,Argon is an inert gas.
Answer:
The outermost (valence) shell of argon has eight electrons, making it exceedingly stable and, thus, chemically inert. Argon atoms do not combine with one another; nor have they been observed to combine chemically with atoms of any other element.So argon is an inert gas
Answer:
because argon have 8 electrons in there outmost shell
which is enough to make it stable
Ammonium carbonate solution is added to dilute nitric acid. What is the balanced chemical equation?
What is the most stable element in the universe (in terms of binding energy)?
A. uranium
B. gold
C. iron
D. hydrogen
E. helium
F. lead
G. water
Answer:
C).Iron
Explanation:
Iron has a binding energy of 8.8MeV
Which term best describes the important pieces of information that scientists gather and record during an experiment?
conclusions
data
research
supplies
Answer:
conclusions i think i am not confirmed
Answer:
b-data
Explanation:
right on the unit test review on edge
brainliest???
What is the Molality of a solution prepared by dissolving 84.7 g of KMnO4 (potassium permanganate, an oxidizing agent) in 165 g of water?
a) 0.513 m
b) 11.3 m
c) 0.308 m
d) 3.25 m
e) 0.958 m
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.
A student performs an experiment to determine the molar mass of magnesium oxide. The student repeats the experiment five times and collects the following data: 40.220gmol, 40.654gmol, 40.314gmol, 40.165gmol, and 40.554gmol. What is the relative standard deviation (RSD) for this set of data?
The relative standard deviation for the set of data obtained by the student is 0.470%
The formula for calculating the relative standard deviation is given below as:
Relative standard deviation (RSD) = (S * 100)/x
where S stands for the standard deviation and x is the mean of the data set.
The following are the steps to calculate to determine the relative standard deviation using the given formula:
Step 1: Calculate the mean of the numbers in the data set.
mean, x = sum of numbers / number of numbers
(40.220 + 40.654 + 40.314 + 40.165 + 40.554)/5
mean = 40.381 g/mol
Step 2: Subtract the mean from each number in the data to determine the deviation for each number and then square the deviations.
(40.220 - 40.381)² = 0.0259
(40.654 - 40.381)² = 0.0745
(40.314 - 40.381)² = 0.00449
(40.165 - 40.381)² = 0.0466
(40.554 -40.381)² = 0.0299
Step 3: Sum the squared deviations.
0.0259 + 0.0745 + 0.00449 + 0.0466 + 0.0299 = 0.181
Step 4: Determine the variance by dividing the sum of the squared deviations by the total number of values.
Variance = 0.181/5 = 0.0362
Step 6: Determine the standard deviation of the data by taking square root of the variance.
Standard deviation, S = √0.0362 = 0.190
Step 7: Determine the relative standard deviation by inserting the values in the formula, (RSD) = (S * 100)/x
RSD = (0.190 * 100)/40.381
RSD = 0.470%
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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
20,000 $ give a way but answer this first
Plz
12.Write the basis of naming of the following elements. 1.Neptunium,2.Mendelevium,
Answer:juhygjdkeExplanation:
Mendelevium is named for Dmitri Mendeleev who produced one of the first periodic tables.
Abelson first found neptunium in 1940 after uranium had been bombarded by neutrons from the cyclotron at Berkeley, California. ... The element was named after the planet Neptune, which is the first planet beyond Uranus.
Answer in explanation
Explanation:
neptunium was named after the discovery of the planet neptune in september 23 1846
mendelevium was named as dimitri mendeleev
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.
How does a hypothesis differ from a scientific theory? (1 point)
O Hypotheses can change with new evidence, but theories remain constant.
O Theories always lead to the development of new scientific ideas.
o Hypotheses are testable, while theories only exist conditionally.
o Theories are well established with lots of evidence to support their claims.
Answer:
the answer is actually D. (theories are well established with lots of evidence to support their claims)
Explanation:
i just took the quiz
A hypothesis is a presented reason for a phenomenon based on limited proof and evidence. A scientific theory is an elucidation of an element that has been constantly experimented with and confirmed per scientific approach.
Theories are well established with lots of proof to back their assertions.
What is the difference between the theory and hypothesis?Scientific theories are established based on the evidence and repetitive experimental procedures to prove and establish them correctly.Theories can change over time as new supporting evidence are found or new procedures are established to amend the old theory.A scientific theory recapitulates a hypothesis that has been reinforced with repeated experiments and observations.A hypothesis should be an instinctive justification or the potential correlation that lies between several phenomena and depends on the scientific theory.Therefore, option D is correct.
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Which of the following are considered elements:
Answer:
considered as element
Helium He
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
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:
...
