Answer:Deforestation, Pollution, Water pollution, Overpopulation, Public health, Global warming, Disposal of wastes
Explanation:
How long does it take light from the sun to reach Earth?
8 minutes 20 seconds
it's instant
7 years 20 days
about an hour
Answer:
8 minutes and 20 seconds
Check all reasons why a syringe was a good
choice of tool in this experiment.
It has volume markings that can be read.
It will not easily leak gas.
The volume can change.
DONE
Answer : All Choices And Then The First Two
A syringe was a good choice of tool in this experiment.
It has volume markings that can be read.It will not easily leak gas.A syringe is a simple reciprocating pump consisting of a plunger (though in modern syringes, it is actually a piston) that fits tightly within a cylindrical tube called a barrel
How is syringe made?To manufacture plastic syringes, the machinery required will be injection moulding machines, set of Multi cavity moulds and sterilization chamber. Polypropylene granules are fed into an injection-moulding machine, where they are plasticized and then injected into a Multi cavity mould.
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Help! Drag and drop the answer into the box to match each method of how to separate solutions to its description.
Answer:
1) D 2) A 3) C
Explanation:
Determine the mass of oxygen produced in the decomposition of 25.0 g of potassium
chlorate, which would also yield the formation of potassium chloride. Show steps please!
Answer:
9.80g of O2.
Explanation:
Step 1:
The balanced equation for the reaction. This is given below:
2KClO3 —> 2KCl + 3O2
Step 2:
Determination of the mass of KClO3 that decomposed and the mass of O2 produced from the balanced equation. This is illustrated below:
Molar Mass of KClO3 = 39 + 35.5 + (16x3) = 122.5g/mol
Mass of KClO3 from the balanced equation = 2 x 122.5 = 245g
Molar Mass of O2 = 16x2 = 32g/mol
Mass of O2 from the balanced equation = 3 x 32 = 96g.
From the balanced equation above, 245g of KClO3 decomposed to produce 96g of O2.
Step 3:
Determination of the mass of O2 produced in the decomposition of 25.0g of KClO3. This is illustrated below:
From the balanced equation above, 245g of KClO3 decomposed to produce 96g of O2.
Therefore, 25g of KClO3 will decompose to produce = (25x96)/245 =
9.80g of O2.
Therefore, 9.80g of O2 is produced from the decomposition of 25g of KClO3.
6) Find the pH of the following solutions:
a) 0.00010 M HClO4
b) 2.35 x 10-3 M HI
c) 4.678 x 10-5 M HNO3
d) 0.0000877 M HCl
e) 0.00020 M HF
f) 0.0000061 M H3O+
g) 4.3 x 10-3 M NaOH (This is a base! Remember you will be finding pOH first!)
h) 6.7 x 10-9 M KOH (This is a base! Remember you will be finding pOH first!)
i) 0.00044 M HCl
j) C
Answer:
pH is the negative logarithm of hydrogen (oxonium) ion concentration of aqueous solutions.
Explanation:
Recall that pH is defined as the negative logarithm of hydrogen ion concentration. We are going to apply that definition here.
a) 0.00010 M HClO4
pH= -log[0.00010]
pH= 4
b) 2.35 x 10-3 M HI
pH= -log[2.35 x 10-3 ]
pH= 2.63
c) 4.678 x 10-5 M HNO3
pH= -log[4.678 x 10-5]
pH= 4.3
d) 0.0000877 M HCl
pH=-log[0.0000877]
pH= 4.1
e) 0.00020 M HF
pH= -log[0.00020]
pH= 3.7
f) 0.0000061 M H3O+
pH= -log[0.0000061]
pH= 5.2
g) 4.3 x 10-3 M NaOH
pOH= -log[OH^-]
pOH= -log[ 4.3 x 10-3 ]
pOH= 2.4
But
pH + pOH =14
Therefore
pH= 14-pOH
pH= 14 -2.4
pH= 11.6
h) 6.7×10^-9 M KOH
pOH= -log[OH^-]
pOH= -log[ 6.7 x 10-9 ]
pOH= 8.2
But
pH + pOH =14
Therefore
pH= 14-pOH
pH= 14 -8.2
pH=5.8
I) 0.00044M HCl
pH= -log[0.00044]
pH= 3.4
Answer: A. 4 B. 2.6 C. 4.3 D. 4.1 E. 3.7 F. 5.8 G. 11.6 H. 5.8 I. 3.4
Explanation:
A. 0.00010 M HClO4
pH = -log [1.0 x 10^-4]
= 4 - log 1 = 4
B. 2.5 x 10^-3 M HI
pH = -log [2.5 x 10^-3]
= 3 - log 2.5
= 3 - 0.398 = 2.6
C. 4.678 x 10^M HNO3
pH = -log [4.678 x 10^-5]
= 5 - 0.7 = 4 .3
D. 0.0000877M HCL
pH = - log [8.77 x 10^-5]
= 5 -0.943 = 4.057 =4.1
E. 0.00020M HF
pH = -log [2.0 x10^-4]
= 4 - 0.301 = 3.7
F. 0.0000061M H3O+
pH = - log [ 6.1 x 10^-6]
= 6 -0.785 = 5.2
G. 4.3 x 10^-3 M NaOH
Finding pOH first , we have
pOH = - log [4.3 x 10-3]
= 3 - 0.633 = 2.4
pH + pOH = 14
pH = 14 - 2.4 = 11.6
H. 6.7 x 10^-9 M KOH
Finding pOH, we have,
pOH = - log [6.7 x 10^-9]
= 9 - 0.826 = 8.17 = 8.2
pH + pOH = 14
pH = 14 - 8.2 = 5.8
I. 0.00044 M HCl
pH = -log [ 4.4 x 10^-4]
= 4 - 0.64 = 3.36 = 3.4
Suppose that a solution is tested for NO2 ion by adding 3M H2SO4 and heating, repeating this process until no further reaction occurs. This solution
is then analyzed for NO3 ion by adding FeSO4 solution and more H2SO4, heating the test tube and its contents. The NO3 ion reaction is positive. In this case, is it accurate to state that NO3 ion was present in the original solution? Briefly explain. Write appropriate equations to support your answer.
Answer:
The correct equation will be "[Fe(H2O)5]²⁺ + NO → Fe(H2O)5NO]²+ (brown ring) ".
Explanation:
For NO₂, the addition of H₂SO₄ forms HNO₂ comprising NO gas as well as HNO₂, the equation will be:
⇒ NO₂⁻ + 2H⁺ → HNO2
⇒ HNO₂ + H₂O + H⁺ → HNO₃ + NO
For NO₃⁻,
NO₃⁻, Fe₂+ oxidized to Fe₃ + then releases NO gas in the existence of H₂SO₄
⇒ 3Fe₂⁺ + 4H⁺ + NO₃⁻ → 3Fe₃⁺ + NO + 2H₂O
Brown ring forming establishes NO3- presence in the initial test sample,
⇒ [Fe(H2O)5]²⁺ + NO → Fe(H2O)5NO]²+ (brown ring)
Which line-angle formula represents an alkene?
Answer:
Option 3.
Explanation:
Alkenes are generally unsaturated hydrocarbon with carbon to carbon double bond (C=C).
From the options given above, only option 2 and 3 contain carbon to carbon double bond (C=C).
Option 2 is called a benzene ring and not an alkene. Benzene are not classified as alkenes because the double bond between the carbon can not be broken i.e benzene does not undergo addition reaction like the alkenes. Benzene tends to show more stability than the alkenes.
This leaves us with option 3 as the answer to the question because it contains carbon to carbon double bond (C=C)
True or False: Solar energy is changed into electrical energy in a solar power tower system using mirrors called heliostats that concentrate sunlight onto a central tower.
True
False
Answer: true
Explanation:
Answer:
true
Explanation:
Concentrating solar power (CSP) plants use mirrors to concentrate the sun's energy to drive traditional steam turbines or engines that create electricity. The thermal energy concentrated in a CSP plant can be stored and used to produce electricity when it is needed, day or night.
what temperature in kelvin does 21 of sulfur dioxide occupy if there are 2.5 mol of it at 1.75 atm?
Answer: 179 K
Explanation:
According to ideal gas equation:
[tex]PV=nRT[/tex]
P = pressure of gas = 1.75 atm
V = Volume of gas = 21 L
n = number of moles = 2.5
R = gas constant =[tex]0.0821Latm/Kmol[/tex]
T = temperature in Kelvin = ?
[tex]T=\frac{PV}{nR}[/tex]
Putting the values , we get :
[tex]T=\frac{1.75atm\times 21L}{2.5\times 0.0820 L atm/K mol}=179K[/tex]
Thus temperature in kelvin is 179 for 21 L of sulfur dioxide occupy if there are 2.5 mol of it at 1.75 atm
Which of the following is most likely an indication of a chemical change?
A. A loud sound when an MP3 player is turned on
B. A loud sound when someone claps their hands
C. A loud sound when a starter's pistol is fired at a race
D. A loud sound when a large object falls to the ground
Hello there!
Question: Which of the following is most likely an indication of a chemical change?
Answer Choices:
A. A loud sound when an MP3 player is turned on.
B. A loud sound when someone claps their hands.
C. A loud sound when a starter's pistol is fired at a race.
D. A loud sound when a large object falls to the ground.
Correct Answer:
C. A loud sound when a starter's pistol is fired at a race.
Reasons:
A would not be correct since an MP3 player is a mechanical object and does not mix any substances that create a reaction.
B would not be correct since clapping hands causes a loud sound due to two forces slamming together and causes a disturbance in the air.
D would not be correct since a large object falling to the ground does not indicate any chemical reactions or changes since its merely the result of a mass hitting another mass.
C would be correct since the gunpowder mixes with other substances inside the pistol's chamber and causes and explosion, and explosions are part of a chemical reaction indicators.
Which of the following is a way that minerals are used?
a industry
b construction
С. technology
all of the above
Please select the best answer from the choices provided
Minerals are used in industry, construction and technology. Therefore, the correct option is option D.
What are minerals?Often created by inorganic processes, a mineral is a naturally occurring homogenous solid having a specific chemical composition as well as a highly organised atomic arrangement. About 100 of the known mineral species—the so-called rock-forming minerals—make up the majority of the known mineral species, which number in the thousands.
A mineral is different from its laboratory-produced synthetic counterparts since it must by definition form through natural processes. For instance, a specimen that seems homogeneous to the unassisted eye may disclose many mineral components when examined under a microscope or when subjected to X-ray diffraction methods. Minerals are used in industry, construction and technology.
Therefore, the correct option is option D.
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What would most likely happen if the amount of carbon dioxide in Earth's atmosphere were severely decreased? A. Plants would grow at an increased rate. B. Ice would cover most of the planet. C. The number of hurricanes and tornadoes would increase. D. The air pressure would drop dramatically worldwide.
Many functions of the nervous system require you to think about them to make them happen and are called ____ ?
Which best describes a force?
a vector with magnitude and direction
a vector with speed and strength
a vector with direction only
a vector with strength only
Mark this and retum
Save and Exit
Next
Submit
Answer:
a vector with speed and strenght
Explanation:
Answer:
Explanation:
A
What process does the equation represent?
U92235+n01→T52137e+Z4097r+2n01
a.) alpha emission
b.)fusion
c.) nucleosynthesis
d.) fission
The answer is d.) fission :)
The equation represents the fission process. In fission the energy is gained by dividing atoms.
Alpha emissionIn this process, the parent isotope emits 2 neutron and 2 proton.
The equation is represented as:
[tex]^{A}_{Z} X \rightarrow ^{A - 4}_{Z - 2} Y + {^{4}_{2}} He[/tex]
FusionIt is the combination of two or more smaller atoms to create a larger one. Fusion require high temperature and pressure (conditions).
The equation is represented as:
[tex]2{^{2}_{1}} H \rightarrow ^{3}_{2} He + ^{1}_{0} n[/tex]
NucleosynthesisThe process in which new atomic nuclei created from pre-existing neutron, proton and nuclei is called Nucleosynthesis.
Fission
It is a heavy nucleus which splits up in to form two lighter nuclei.
The equation is represented as:
[tex]^{235}_{92}U + ^{1}_{0} n \rightarrow ^{141}_{56} Ba + ^{92}_{36} Kr + 3 ^{1}_{0} n[/tex]
So the given equation in question satisfies this equation. So fission represent the process.
Thus, from above conclusion we can say that the equation represent fission process. So option D is correct answer.
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An oxidation reaction requires which of the following for most common
Answer: Oxygen
Explanation:most common fires require oxygen for a fire to start. With out oxygen the fire will go out.
An oxidation reaction typically requires an oxidizing agent, which is a substance which accepts electrons and causes the oxidation of another substance.
What is an Oxidation reaction?Any chemical reaction in which electrons are transferred from one substance to another is called an oxidation reaction. The process of losing electrons is called oxidation, and the process of gaining electrons is called reduction. In other words, electrons are lost during oxidation while they are gained during reduction.
Redox reactions, which always involve these two processes, are called. Oxidation processes can lead to a number of chemical changes, including the formation of new chemical bonds, the release of energy, or the synthesis of new compounds. Oxidation reactions are involved in many natural processes, such as burning, rusting, and cellular respiration.
Therefore, an oxidation reaction typically requires an oxidizing agent, which is a substance which accepts electrons and causes the oxidation of another substance.
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Earth would fly off into space in a straight line if the ______________________________
between Earth and the Sun ended.
Answer:
Gravity
Earth would fly off into space in a straight line if the gravity
between Earth and the Sun ended
Explanation:
The Earth's orbit is made through gravity and inertia. If gravity between the Sun and Earth had ended, inertia would make the Earth travel in a straight line because there is no gravity to pull it towards the sun and keep it in motion.
What’s the oxidation number for S2O3
Answer:
+4 +3(-2) = -2
Explanation:
This is chemistry help
Why does BROMINE have a smaller atomic radius then SCANDRUM
Answer:
So while Bromine has 15 more electrons, they're occupying about the same space as Calcium's and since Bromine's nucleus has a stronger positive charge, it pulls that shell closer in, making Bromine overall smaller.
Explanation:
Suppose you mix 75 g of water at 15 ℃ with 25 g of water at 75 ℃. Predict the final temperature from the choices below. Explain your choice.
A. 30 ℃ b. 45 ℃ c. 60 ℃
Calculate the pH of a 0.0150 M HNO3 solution. Assume HNO3
dissociates completely in water.
pH =
Answer:
~1.82381
Explanation:
Since it dissociates in water there will be equally amounts of H and NO3. Therefore, there will be 0.0150 M H+ ions. Simply take the -log(H+) = pH, so -log(0.0150) = ~1.82
The pH of the given solution when HNO3 dissociates completely in water is 1.82381.
Calculation of the pH:Since it is the 0.0150 M HNO3 solution. Also we assume that HNO3
dissociates completely in water. So there should be equivalent amount of H and NO3.
So, it can be like
-log(H+) = pH,
so -log(0.0150)
= 1.82
Hence, we can conclude that The pH of the given solution is 1.82381.
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Which statements describe both male and female reproductive systems? Select three options
Answer:
A:The reproductive system produces hormones.
B:The reproductive system transports reproductive cells.
C:The reproductive system produces reproductive cells.
Explanation:
A:The reproductive system produces hormones. : The reproductive organs ovaries in females and testes in males produces hormones. The ovaries produce estrogen and progesterone and testes produce testosterone.
B:The reproductive system transports reproductive cells. : The ovaries in females transfers an egg into the fallopian tube and testes in males secrete sperms at the time of copulation the fertilization of egg and sperm leads to the development of zygote the precursor of new life.
C:The reproductive system produces reproductive cells.: The ovaries undergo oogenesis and in testes spermatogenesis takes place to develop egg and sperms respectively.
Explanation:
A sample of tin (Cp = 0.227 J/g•°C) is placed in a freezer. Its temperature decreases from 15.0°C to −10.0°C as it releases 543 J of energy. What is the mass of the sample? Round your answer to three significant figures. gA sample of tin (Cp = 0.227 J/g•°C) is placed in a freezer. Its temperature decreases from 15.0°C to −10.0°C as it releases 543 J of energy. What is the mass of the sample? Round your answer to three significant figures. gA sample of tin (Cp = 0.227 J/g•°C) is placed in a freezer. Its temperature decreases from 15.0°C to −10.0°C as it releases 543 J of energy. What is the mass of the sample? Round your answer to three significant figures.
Answer:
95.7
Explanation:
Got it right edg2020
Answer:
95.7
Explanation:
Just as confirmation, did indeed get it right
What is the pressure in atmospheres of 6.0 moles
of an ideal gas if its volume is 2.0 liters and its
temperature is at 80.0°C? Record your answer to
the nearest atmosphere.
Answer: 87atm
Explanation:
Ideal gas equation is given by the formular: PV = nRT
P = ? V = 2L , n = 6moles
R = 0.082057 L.atm/mol/K
T = 80° C + 273.15 = 353.15K
Let's make 'P', the subject of formula,
P = nRT/ V
= 6mol x 0.082057 L.atm/mol/K.
x 353.15K / 2L
= 86.9 approximately
= 87atm
Kendrick sees a display of rock samples at a museum. The information included in the display is as follows:
Rock A formed from liquid rock.
Rock B formed from small pieces of rock in a different place.
Rocks A and B formed at about the same time.
Are Rocks A and B the same or different types of rock?
The rocks are
Answer:
Different types
Explanation:
Because it's in a different place
List, in order, the types of light in the electromagnetic spectrum from largest wavelength to smallest wavelength.What is white light?
Answer:
The electromagnetic spectrum includes, from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, X-rays, and gamma-rays. White light is apparently colorless light, for example ordinary daylight. It contains all the wavelengths of the visible spectrum at equal intensity.
Explanation:
Answer:
Gamma rays, x rays, ultraviolet rays, visible light, infrared light, microwaves, and radio waves.
White light is a colorless light that contains all of the wavelengths of the visible spectrum.
Explanation:
I'm sure of my answers.
Hope this helped lots and lots,
sincerely, me
Which freshwater ecosystem is least productive?
O A. Stream
B. Bog
C. Marsh
D. Swamp
SUBMIT
Compare and contrast the goals of the General Mining Law of 1872 and the proposed Hardrock Mining and Reclamation Act of 2009.
Answer: seen below
Explanation:
the goals of the General Mining Law of 1872 state that, anyone can stake mining claims on federal land, and they pay no more than $5 an acre while they keep 100% of profits with little to no environmental provisions.
Taxpayers pay for clean up of sites.
While the goals of proposed Hardrock Mining and Reclamation Act of 2009 includes, Increasing acreage of lands off limits to exploration and development. Protecting of National Parks and National Monuments is essential. Giving land managers the ability to balance mineral activities with other uses of public land. Giving state, local and tribal government the ability to put lands off limits to mining although, this bill never became law.
Which process was responsible for producing gases in the early atmosphere?
Answer: The early atmosphere
Explanation: Its early atmosphere was probably formed from the gases given out by volcanoes. It is believed that there was intense volcanic activity for the first billion years of the Earth's existence. The early atmosphere was probably mostly carbon dioxide, with little or no oxygen.