Answer:
After 7.648 days, you will see one quarter.
Explanation:
1 → 0.5 → 0.25
Since half life of radon-222 is 3.824 days, you need twice this time to get one quarter at the end.
2 ⋅ 3.824 = 7.648 days.
Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? a. The chlorofluorocarbons act like ultraviolet radiation causing large amount of ozone to be produced. b. The chlorine from the chlorofluorocarbons reacts with free molecules of oxygen causing a stop in ozone production. c. Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone. d. Chlorofluorocarbons absorb ultraviolet radiation, preventing the formation of ozone.
Answer:
Why are small quantities of chlorofluorocarbons so harmful to the ozone layer? Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone.
Explanation:
The statement for small quantities of chlorofluorocarbons so harmful to the ozone layer is "Free oxygen atoms can replace the chlorine in chlorine monoxide, releasing a free atom of chlorine which can then recombine with an oxygen atom in ozone, destroying more ozone."
What is ozone layer?The ozone layer is a thin layer of air in the Earth's atmosphere that absorbs nearly all of the sun's damaging UV radiation.
What is CFCs?CFCs (chlorofluorocarbons) are harmless and nonflammable compounds made up of carbon, chlorine, and fluorine atoms.
The earth's protective ozone layer is destroyed by chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and halons, which shield the earth from damaging ultraviolet (UV-B) rays released by the sun. CFCs and HCFCs also warm the earth's lower atmosphere, causing global climate change.
When some substances are exposed to high UV radiation in the stratosphere, they emit chlorine or bromine. Ozone-depleting chemicals are compounds that contribute to ozone depletion (ODS). Chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), carbon tetrachloride, and methyl chloroform are examples of ODS that produce chlorine. Halons and methyl bromide are two ODS that emit bromine.
Because there isn't much ozone in the atmosphere, what little there is is critical for protecting the Earth's surface from excessive UV light from the Sun. It turns out that it reacts with chlorine, which means that chlorine effectively eliminates ozone.
When the chlorine in CFCs combines with ultraviolet light, it releases chlorine, which then reacts with ozone, reducing the protection humans get from ultraviolet light, allowing more CFCs to release chlorine, and so on. Multiple ozone molecules will interact with one free chlorine atom, which is free because UV light has hit the CFC molecule. As a result, the damage it can cause is likely to be significantly more than you might imagine.
Hence the correct option is c.
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what is the main function of this organelle in the cell?
Answer:
[tex]to \: use \: energy \: from \\ \: sunlight \: to \: make \: sugars.[/tex]
Explanation:
[tex]the \: main \: function \: of \: this \: organelle \\ \: in \: the \: cell \: is \: to \: use \: energy \: from \\ \: sunlight \: to \: make \: sugars.[/tex]
what turns colour in an acid and base
Answer:
Chemists use a solution called Universal Indicator to identify acids and bases. ... The Universal Indicator Color Guide shows that Universal Indicator turns red when it is added to a strong acid, it turns purple when it is added to a strong base, and it turns a yellowish-green when it is added to a neutral solution.
Explanation:
Answer:
Phenolphthalein
Explanation:
What’s this called please help
Answer:
the answer is a linear
Explanation:
heres a graph different ones at this link
Molecules in a liquid are:
closer together than in a gas
moving more quickly than in a solid
moving more slowly than in a gas
all of the above
Please help!!!
Answer:
all of the above
Explanation:
How would you arrange the objects below from greatest to least volume?
A balloon
A water bottle
A bottle of soda
A rock
Answer:
A balloon
A bottle of soda
A rock
A water bottle
Explanation:
the ability for a substance to rust is
a. oxidation
b.rustability
c.magnetic attraction
d.reactivity
Answer:
i think it is letter b. rustability but not so sureeee
Find an element that has the same
number of valence electrons as
Thallium (T1).
i need the answer nowww
Answer:sodium
Explanation: because its not hard to look on the PERIODIC TABLE
when do meanders form in a river?
A.young
B.old
C.mature
D.rejuvenated
Answer:
The formation of a meander. As the river erodes laterally, to the right side then the left side, it forms large bends, and then horseshoe-like loops called meanders . The formation of meanders is due to both deposition and erosion and meanders gradually migrate downstream.
What are the reactants of photosynthesis?
Answer:
The photosynthesis chemical equation states that the reactants (carbon dioxide, water and sunlight), yield two products, glucose and oxygen gas. The single chemical equation represents the overall process of photosynthesis.
Explanation:
Which is the IUPAC name for NO?
nitric oxide
binitrogen oxide
dinitrogen dioxide
nitrogen monoxide
The IUPAC name for NO is nitric oxide. The correct option is A.
What is IUPAC naming?The International Union of Pure and Applied Chemistry (IUPAC) is a global organization that represents chemistry as well as related sciences and technologies.
The chemical compound's identity is represented by its common and IUPAC names, which differ from one another. Every chemical compound has multiple names.
Complete the following step-by-step response: The IUPAC nomenclature is a standardized name given to organic compounds in accordance with official naming rules.
Nitric oxide, also known as NO, is a colorless gas. It is one of the most important nitrogen oxides.
Nitric oxide is a free radical, which means it has an unpaired electron, which is sometimes represented in its chemical formula by a dot.
Thus, the correct option is A.
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Answer:
D: Nitrogen Monoxide
Explanation:
There's one Nitrogen atom and one Oxygen atom
25 POINTS
Boyd takes additional measurements of the mass of product formed in a reaction. He uses a balance that has smaller graduations than the first balance he used.
What is Boyd most likely trying to change?
Options:
He is trying to increase his accuracy but not his precision.
He is trying to increase his precision but not his accuracy.
He is trying to decrease his precision and increase his accuracy.
He is trying to increase his precision and decrease his accuracy.
Answer:
The correct option is A: "He is trying to increase his accuracy but not his precision"
Explanation:
Accuracy of measurement is when the value of the measurement is close to the actual value of that measurement while precision is when the experiment is repeated using the same instrument but obtaining different values.
When Boyd changed the weighing balance in his experiment to a smaller one, the smaller weighing balance has better accuracy (smaller graduations) than the initially used one because the smaller weighing balance will provide a value close to the actual value of the mass of the product. If he had, however, repeated the experiment without changing the weighing balance, he would have sought to increase his precision.
From the description above, it can be said that Boyd was trying to increase his accuracy but not his precision
Answer:
The correct option is A: "He is trying to increase his accuracy but not his precision"
Explanation:
right on EDGE 2021
helppppppppppppp plzzzzzzzz Identify each structure based on its label.
Compound A is a
amine.
Compound B is a
amine.
Compound C is a
amine.
Compound D is
.
Answer:
kldja
Explanation:
A.) primary
B.) tertiary
C.) secondary
D.) ammonia
edge2020
Which of the following is NOT an example of a chemical change? *
O Corrosion
O Grinding
O Combustion
O Rust
Help pleaI’ll give brainliest
Which element has the
greatest number of valence electrons available for bonding?
O selenium
Oboron
O calcium
O chlorine
1. A pile of boxes exerts a force of 500 newtons downward on the floor. The boxes are not in motion. What is the normal force on these boxes?
2. Norman drags a stubborn dog by his leash with a force of 200 newtons. The dog is slowly moving towards Norman. What do you know about the force exerted by the dog?
3. A baby grand piano sits in a music room. The piano exerts a force of 3500 newtons downward. Isaac tells his friends that he is strong enough to lift the piano off the floor. How much force will he have to use to lift the piano?
4. Ms. Holt is dragging a box of assessments across the floor using a force of 70 newtons. The frictional force acting against the box is 50 newtons. What is the net force on the box?
5. A bicycle is sitting motionless in the driveway. What is the net force acting on this bike?
6. Maria drops a box that exerts of force of 300 newtons downward on a table. The normal force acting on the box from the table is 250 newtons. What will happen to the table and the box? What is the net force of the box?
7. Anna is riding her bike, moving at a constant velocity of 3 miles per hour to the south. She is using 200 N of force to pedal her bike. A gust of wind blowing in the same direction she is traveling suddenly exerts a force of 20 Newtons on her. What will happen to her motion? (hint: Use the term accelerate OR decelerate in your answer.)
8. Mrs. Fedde is riding her bike, moving at a constant velocity of 5 miles per hour to the north. She is using 300 N of force to pedal her bike. A gust of wind blowing in the opposite direction she is traveling suddenly exerts a force of 50 Newtons on her. What will happen to her motion? (hint: Use the term accelerate OR decelerate in your answer.)
which element has the electron configuration of 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10 5p6 6s2 4f14 5d10 6p6 7s2 5f14 6d8
Answer:
Darmstadtium
Explanation:
An element with the electronic configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶7s²5f¹⁴6d⁸ has 110 electrons in its electron shells.
Since the element is a neutral atom, this number is also equal to its atomic number. Therefore, its atomic number is 110.
The element in the period table that has an atomic number of 110 is Darmstadtium, a d-block element, thus a transittion metal. It also belong to period 7 in the Periodic table of elements.
The element that has the electron configuration is Darmstadtium.
Electronic configuration:Since An element with the electronic configuration 1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁶7s²5f¹⁴6d⁸ contains 110 electrons in its electron shells.
Also, the element should be a neutral atom, this number should also equal to its atomic number. Therefore, its atomic number is 110.
The element in the periodic table that has an atomic number of 110 is Darmstadtium, a d-block element, thus a transition metal.
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What is Mercury's proximity to the sun
Answer:
46.943 million km
Explanation:
From an average distance of 36 million miles (58 million kilometers), Mercury is 0.4 astronomical units away from the Sun.
Answer:
29.169 million miles
Explanation:
From an average distance of 36 million miles(58 million kilometers,Mercury is 0.4 astronomical units away from the sun.
3. In an exercise to teach students how to use and analytical balance, the instructor
gives a student a quarter which has been pre-weighed as 5.6026 g. The weight that the
student obtains for the same quarter is 5.6013 g. What is the percent error in the
students reading?
Answer:
The percent error is 0.023%.
Explanation:
Pre-weighed of a quarter is 5.6026 g.
The weight that the student obtains for the same quarter is 5.6013 g.
We need to find the percent error in the students reading. It is given by the formula as follows :
[tex]\%=\dfrac{|\text{original value-calculated value}|}{\text{original value}}\times 100[/tex]
Putting all the values, we get :
[tex]\%=\dfrac{5.6026 -5.6013 }{5.6026 }\times 100\\\\\%=0.023\%[/tex]
So, the percent error is 0.023%.
The first column of the periodic table is called the
Calculate the enthalpy change to raise the temperature of 180.0 g of water from 10.0°C to 40.0°C. The molar heat capacity for water is 75.3 J/Kmol. a. What values have you been given? b. What value are you trying to find? c. Which heat equation do you need? d. Now solve the problem.
Answer:
22572J
Explanation:
a) The following values have been given:
Mass of water = 180.0g
Initial temperature = 10°C
Final temperature = 40°C
molar heat capacity for water = 75.3J/Kmol
To calculate the specific heat capacity of water (c), we divide the molar heat capacity by molar mass of water (18g/mol)
That is; 75.3/18
= 4.183 Jg/K
b) The enthalpy change denoted by ∆H is the value we are trying to find.
c) To find enthalpy change (∆H), we use the formula:
∆H = m × c × ∆T
Where; m= mass
c= specific heat capacity
∆T= change in temperature =
(final temp - initial temp)
∆H = m × c × ∆T
∆H = 180 × 4.18 × (40-10)
∆H = 180 × 4.18 × 30
∆H = 22572J
Which of the following is an example of quantitative data?
A.five eggs in each nest
B.oval-shaped eggs
C.small eggs
D.blue eggs with white specks
(True/False) Solid Potassium Chloride, KCl (s), consists of equal numbers of positive Potassium ions (K+), and negative Chloride ions (Cl-) arranged in three dimensional networks called crystals. (6 Pts)
Answer:
true
Explanation:
Which of these statements describes a chemical property?
Answer:
it rusts when exposed to air
Answer:
A
Explanation:
10 POINTS
Which tool can be used to measure the volume of a liquid to one decimal place?
Options:
a beaker
a graduated cylinder
an Erlenmeyer flask
a test tube
How to find the number of atoms?
To find the number of atoms, we multiple the number of mols by Avogadro's number, about 6.02x10^23
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Answer:
to calculate the numbers of atoms in a sample, divide it's weight in grams by the amu atomic mass from the periodic table, then multiply the result by avogadro's number: 6.0 × 10^24
An unknown substance has a volume of 2 cm3 and a mass of 38.6 grams.
What is the density of the sample?
Answer:
The answer is 19.3 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{38.6}{2} \\ [/tex]
We have the final answer as
19.3 g/cm³Hope this helps you
what is the journey around the sun by earth called, and how long does it take?
Answer:
Its called ecliptic and it takes 365 days
Explanation:
Answer:
The journey around the Sun by Earth is called a revolution, it takes 365-and-a-quarter-days.
Explanation:
How do I put Chlorofluorocarbons in a sentence?
Answer: Here are some examples
Explanation:
1. In the southern spring, ozone is destroyed above Antarctica, mainly by manufactured compounds called chlorofluorocarbons (CFCs )
2. It is now generally accepted that the loss of stratospheric ozone is caused by chemical reactions initiated by chlorofluorocarbons.
3. Your refrigerator and other home appliances emit Chlorofluorocarbons, or CFCs, as do aerosol spray cans.
Hope this hlps!
Explanation:
To be able to put the chemical term chlorofluorocarbons in a sentence, you must first understand what the chemical species denotes.
We know chlorofluorocarbons are a group of compounds that consists of atoms of chlorine, flourine, and carbon.
Now, here are some sample sentences;
Chlorofluorocarbons are one of the leading causes of ozone depletion in the atmosphere. Most national governments are putting measures in place to check the use of chlorofluorocarbons in industrial manufacturing.If we can innovate a substitute for chlorofluorocarbons, the environment would be safer.HELP ASAPP JUST TELL ME WHAT TO PUT IN THE MISSING SPACES words(cell,microorganisms,micrometer,microscopic,molecule)
Answer:
microorganisms, molecule, microscopic, cell, micrometer
Explanation:
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