Answer:
1/8th = 12.5%
Explanation:
Three half lives would be 1/2 * 1/2 * 1/2 = 1/8 th of original
why might it be unwise to drink water straight from a pond
Answer:
it is because of the bacteria and different things that go into waters such as ponds, rivers, lakes, seas, oceans, streams, and other body of waters and I should also add the chemicals that go into them as well
Explanation:
5. Consider the following experiment: A block of iron with an initial mass of 50 g is placed in a sealed container of pure oxygen. After several days, the block is red in color and has a mass of 74 g. Are these observations a violation of the law of conservation of mass? Justify your answer.
The observation in the illustration remains in accordance with the law of conservation of mass assuming that moisture is present in the container.
What is the law of conservation of mass?The law state that mass can neither be created nor destroyed. However, mass can be converted from one form to another.
In this case, the ion was placed in a container of pure oxygen. Assuming that moisture is present, iron reacts with oxygen to form rust according to the following equation:
[tex]4Fe + 3O_2 + 6H_2O --- > 4Fe(OH)_3[/tex]
The rust formed will weigh more than the initial weight of the iron.
Without the presence of moisture, one can effectively conclude that the observation violates the law of conservation of mass.
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what is the difference between soft water and hard water
Answer:
soft water can leath with soap whiles hard water cannot be leathers with soap
Answer:
Hard water is water with excess calcium and magnesium, while soft water lacks harsh minerals that can hurt your body.
Explanation:
Also, in hard water, soap is not so effective (little or no foam) and in soft water soap is easily effecive (foams easily).
Name these compounds according to IUPAC. (ASAPP)
Propanal and acetone are the IUPAC names for the chemical.
What is the difference between propanal and acetones?Propanal, commonly known as propanaldehyde, is an aldehyde with one double bond and one oxygen atom.
Acetone is a ketone compound. R2CO is the functional group of ketones.
Thus, Propanal and acetone are the IUPAC names for the chemical.
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Can diamond sublime at any pressure up to 1011 kPa? Explain your answer.
Yes, at high temperature and pressure (1011 kpa), diamond can change directly (sublime) into gaseous form.
What is a diamond?Diamond is a solid form of the carbon element with its atoms arranged in a crystal structure called diamond cubic.
Diamond has some interesting properties, which is written below;
Diamond is extremely hard and non volatile substanceDiamond can sublime (change directly to gaseous sate)A diamond interacts with oxygen in the air and disappears to form carbon dioxide.
Thus, at high temperature and pressure (1011 kpa), diamond can change directly (sublime) into gaseous form.
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(iii) Describe one test for the presence of water
Answer:
Anhydrous copper sulphate.
Explanation:
In the presence of water anhydrous copper sulphate , a white powder, turns to blue.
Using the rxn below determine the following: What is the limiting reagent, theoretical yield of nitic oxide, and how many grams of excess reagent remain when producing nitric oxide when using 4.65g of ammonia to react with 4.25g of oxygen?
5 mols of O_2 need 4 mol NH_3
As mols of ammonia are less Ammonia is limiting reagentNow
Moles of Ammonia
Given mass/Molar mass4.65/170.3molMoles of NO=0.3mol
Mass of NO
0.3(30)9gSo
Moles of Oxygen
4.25/320.13molRemaining moles
0.3-0.13=0.17Mass
0.17(32)5.44gYield
5.44-4.250.79gName the following compound:
CH₂-CH-CH₂ - CH₂ - CH3
1
2
CH₂
CH₂
Answer:
methylhexane.
Explanation:
Because thats the answer.
Density is d= m/vol. If a material has a mass of 65.5 g and a volume of 32.5 ml, it has a density of
Using the given formula, the density of the material is 2.015 g/mL
Calculating DensityFrom the question, we are to determine the density of the material
From the given formula
Density = Mass / Volume
And from the given information,
Mass = 65.5 g
and volume = 32.5 mL
Putting the parameters into the equation,
Density = 65.5/32.5
Density = 2.015 g/mL
Hence, the density of the material is 2.015 g/mL.
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what is an atom?Please help
Answer:
It's the basic unit of an element.
something that makes up everything that has mass
Explanation:
(Help!) What is the mass of hydrogen atoms that is measured at 72 u?
Answer:
=71.439911 u
Explanation:
We know that 1 mass of hydrogen atom = 1.00784 u
If it's measured at 72u: 72/1.00784=71.439911 u
Mass of 1 mol hydrogen atoms =1.00784u
Total mass in 72u
72/1.0078471.43uWhat pressure is exerted by 0.375 mol of hydrogen gas in a 4.33 L container at 55.0C?
Answer:
47
Explanation:
Sodium-24 has a half-life of 15 hours. How much sodium-24 will remain in a 36.0-g sample after 45 hours
Answer:
4.5 gm left
Explanation:
45 /15 = 3 half lives (1/2 )^3 =1/8 th
1/8 * 36 = 4.5 gm
An HNO3 (ag) solution has a pH of 1.75. What is the molarconcentration of the HNO3(aq) solution?
⇒ 0.018
-use pH=-log[H3O+]
-solve for H3O+
Protons and neutrons are made from which of the following particles?
Down quarks only
Hadrons
Up quarks and down quarks
Up quarks only
3. fill in: name the organelle or organelles that perform each of the following functions. a. _____________________ convert sunlight to chemical energy. b. the _____________________ and the _____________________ help to support the plant cell and help it to maintain its shape. c. _____________________ store food or pigments. d. the _____________________ converts food into energy. it is found in both plant cells and animal cells.
Organelles are the components of the cells with various functions and roles. The correct blanks are chloroplast, cell wall and vacuole, vacuoles, and mitochondria.
What are the organelles?The organelles are the cell components that have well-defined structures and functions to perform the designated task in the cell activity. Chloroplast is the organelle that converts solar energy into chemical energy through photosynthesis.
The cell wall and the vacuoles provide the structural framework and shape of the cell. The vacuoles also store food pigments in the cell. The mitochondria of the cell convert the food source into energy like ATP.
Therefore, the correct blanks are chloroplast, cell wall and vacuole, vacuoles, and mitochondria.
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Which of the following equation is balanced?
Answer:
2fe2o3+3c=4fe+3co2
Explanation:
because 2×2 =4 fe &2×3=6 so we put it like 3co2
which of the following chemical symbol is that of an element with six electrons in the outermost shell a)Ca b)Cl c)Ne d)S
Answer:
S
Explanation:
Using periodic table (see those little numbers in the upper right? Those are electron 'shells' .... look at the bottom one)
Ca has 2 Cl has 7 Ne has 8 S has 6 in the outermost shell
how many grams of KNO3 can be dissolved in 100g of water at 80c
Answer:
As temperature increases, its solubility increases as well. Notice, however, that it does not increase significantly. In fact, you can expect to be able to dissolve no more than 40 g of sodium chloride per 100 g of water at 80∘C
Explanation:
As temperature increases, its solubility increases as well. Notice, however, that it does not increase significantly. In fact, you can expect to be able to dissolve no more than 40 g of sodium chloride per 100 g of water at 80∘C
d. What is being done to save this species
e. An organization/group that is working towards
Create a commercial that showcases why we should save the manta rays
a. Commercials should be about 30seconds-1 minute. No longer than 30
Answer:
answer
Explanation:
I think it's e hope it right
I NEED HELP ASAP!!!!!!!!!!!!
WITHIN THE HOUR
Thanks
Answer:
A. O, S, Se
Explanation:
They are all considered "other nonmetals," found in row 16 of the periodic table, and are chalcogens. The other options don't have as much in common.
[Then mother noticed that two children who are watching the game are sick and coughing.She told her son to keep distance from those children to avoid getting sick]
1.Observe illustration no.1 and read the caption.Why did the mother ask her son to avoid the kid with cough?
2.Observe illustration no.2 and read the caption.Why did the mother let her son play with the kid with asthma?
please don't report this
Answer:
in illustration 1
the mother told her son not to play with the boy having cough because it is a transferable disease which could cause him also to get sick and would get cough.
while in
illustration 2
the mother let the boy play with the boy having asthma because it is not a transferable disease which wold not affect him or any one else.
Explanation:
this is the reason
#1
Cough is a infectious disease .It spreads through the droplets falling outwards during coughing.If her son stays there for long time he would be affected by cough also or he would get sick .So the mother denied .#2
Asthama is although a disease of lungs but it doesn't spread through air or droplets.It's not infectious .So nothing would happen if her child playsPLEASE HELP I NEED ANSWER ASAP
Mark the oxidation nos
Co=0Cu=2+Then
Co=2+Cu=0Gain of electron is reduction
Copper is reduced .
Option D
describe what happens when water vapour cools to liquid water(change in arrangement,change in movement,change in energy)
Answer:
CONDENSATION When steam is cooled, it releases thermal energy and turns into its liquid state. This process is called condensation.
Explanation:
How many oxygen atoms are in one mole of carbon dioxide
Answer:
abt 2 moles
Explanation:
1 mole of carbon atoms per mole of carbon dioxide = 6.02 x 1023 carbon atoms. 2 mole of oxygen atoms per mole of oxygen atoms = 2 x 6.02 x 1023 oxygen atoms.
What property of copper makes it ideal to create thin sheets of
copper?
Copper is a soft, ductile, and malleable metal that bends and stretches easily without breaking. Copper is a versatile metal for construction and manufacturing because of this.
Hydrogen gas is collected over water at a total pressure of 95.0kPa. The volume of gas collected is 28.0mL at 25.0˚C. Determine the partial pressure of the hydrogen gas if the water vapor pressure is 3.17kPa.
GAS LAW:
Given:
Unknown:
Formula:
Solution:
The partial pressure of the hydrogen gas, if the water vapor pressure is 3.17kPa is 91.83 kPa.
What is Dalton's law of gas?Dalton's law of gas states that total pressure of the mixture of gas is equal to the sun of the partial pressure of the individual gas.
Given that,
Total pressure of hydrogen gas = 95 kPa
Partial pressure of water vapor = 3.17 kPa
Partial pressure of hydrogen gas will be calculated as:
Partial pressure = 95 - 3.17 = 91.83 kPa
Hence required partial pressure is 91.83 kPa.
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Calculate the number of joules released when 75.0 grams of water are cooled from
100.0°C to 27.5°C
Answer:
-22750.5J or -2.28× 10⁴J
Explanation:
q=(75.0g)(4.184J)(27.5°C-100.0°C)
q= -22750.5J
q= -2.28× 10⁴J
What is the color of bromocresol green indicator in a solution with a ph value of 2. 0.
Answer:
The answer would be "Yellow"
Explanation:
Hope this helps!
A gas occupied 780.0 mL at a temperature of 30°C. Several days later, it was measured at
a temperature of 16°C.
What volume did the gas occupy under these new conditions?
Answer:
744.0 mL
Explanation:
Formula obtained from Charles Law :
⇒ [tex]\frac{V_{1} }{T_{1} } = \frac{V_{2} }{T_{2} }[/tex]
===============================================================
Given :
⇒ V₁ = 780.0 mL
⇒ T₁ = 30 °C = 303 K
⇒ T₂ = 16 °C = 289 K
=============================================================
Solving :
⇒ V₂ = 780 × 289 / 303
⇒ V₂ = 225420 / 303
⇒ V₂ = 744.0 mL (approximately)