Answer:
3 moles CH4, and each mole contains 6.02x10^23 molecules and each molecule contains 5 atoms, so there are 5 atoms/molecule x 6.02x10^23 molecules/mole x 3 moles = 9x10^24 atoms
Explanation:
If a patient receives a dose with an activity of 53.8 mCi of technetium-99m for cardiac imaging, how much radioactivity will be left in the patient’s body 72 hours after injection?
Therefore if a patient receives a dose with an activity of 53. 8 mCi of technetium-99m for cardiac imaging, radioactivity will be left in the patient’s body 72 hours after injection is 0.00024
The equation that describes the radioactive decay is:
Ln [A] = -kt + Ln [A]₀
Where [A] could be taken as activity of the source after time t, [A]₀ is initial activity and k is decay constant.
Decay constant could be written as:
k = ln2 / Half-life
k = ln 2 / 6h
k = 0.115h⁻¹
Replacing in decay equation:
ln a = -0.115 x 72 + Ln [53.8]
ln a = - 8.28 + 3. 98
ln a = - 8.28
log a = -4/ 2.303
log a = 1.867
Therefore if a patient receives a dose with an activity of 53. 8 mCi of technetium-99m for cardiac imaging. radioactivity will be left in the patient’s body 72 hours after injection is 1.867
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Xylem cells have thickened walls how does this thickening differ in the two xylem shown in the diagram
The secondary cell wall of the elongated, hollow xylem cells, which are dead, contains lignin.
What functions as the xylem?The specialized tissue in vascular plants called xylem distributes nutrients and water from the plant-soil contact to the stems and leaves as well as serving as a mechanical support system and a storage system. One of the key characteristics that sets vascular plants apart is the xylem's ability to transmit water.
Where can you locate the xylem?Vascular bundles, which are found in both non-woody plants and non-woody sections of woody plants, contain xylem. In woody plants, a meristem known as the vascular cambium lays down secondary xylem. as a component in a starry arrangement rather than a bundle, as in many ferns.
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what is the difference between copper bromide and copper chloride solution when exposed to the flame test ?
Answer:
copper chloride is green
and bromide copper is gray
Explanation:
because the copper(II) ion
what were the 3 constellations that were above the horizon at
9PM on August 31, 2022?
The photoelectron spectra above show the energy required to remove a 1s electron from a nitrogen atom and from
an oxygen atom. Which of the following statements best accounts for the peak in the upper spectrum being to the
right of the peak in the lower spectrum?
(A) Nitrogen atoms have a half-filled p subshell.
(B) There are more electron-electron repulsions in oxygen atoms than in nitrogen atoms.
(C)
Electrons in the p subshell of oxygen atoms provide more shielding than electrons in the p subshell of
nitrogen atoms.
(D) Nitrogen atoms have a smaller nuclear charge than oxygen atoms.
ntc immediately following it Select the one
Answer:
:)
Explanation:
Nitrogen atoms have a smaller nuclear charge than oxygen atoms. The correct option is D.
What is photoelectron spectra?By ionization, a photoelectron spectrum can reveal the relative energies of occupied molecular orbitals. (i.e. electron ejection).
A photoelectron spectrum can also be used to calculate the energy gap between vibrational levels of an electronic state.
Photoelectron spectroscopy is a useful tool because it allows scientists to investigate the properties of matter (gases, solids, and liquids) by measuring electron orbital energies.
The photoelectric effect is the process by which electrons are ejected or released from the surface of materials (usually metals) when light falls on them.
The photoelectron spectra show how much energy it takes to remove a 1s electron from a nitrogen atom and an oxygen atom. The nuclear charge of nitrogen atoms is lower than that of oxygen atoms.
Thus, the correct option is D.
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A runner exerting a running force of 325 N to the right is met with an air resistance force of 45 N to the left. What is the net
force of the runner? (1 point)
O 45 N
O 280 N
O 370 N
O 325 N
The net force of the runner, given the data from the question is 280 N
Data obtained from the questionFrom the question given above, the following data were obtained:
Exerting force = 325 NResistance force = 45 NNet force =?How to determine the net forceThe net force of the runner can be obtained as illustrated below:
Net force = Exerting force - resistance force
Net force = 325 - 45
Net force = 280 N
From the calculation made above, we can conclude that the runner's net force is 280 N
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The net force of the runner would be 280 N.
Hope this helps! Also, if you need help with the other questions regarding this assignment, feel free to check out the study set I made on Quizlet. Thanks and good luck!
Quizlet - "Unit 6: Lesson 2 Newton's First Law QC"
h t t p s : / / q u i z l e t. c o m / 7 3 7 7 5 9 5 5 5 / u n i t - 6 - l e s s o n - 2 - n e w t o n s - f i r s t - l a w - f l a s h - c a r d s / ? n e w
If you change the atomic mass to a whole number and subtract the atomic number from it, what does the answer symbolize?
Answer:
Based on the mass number of an element, one can determine the number of neutrons that element has. The identity of an element implies its number of protons, and thus one can subtract atomic number from mass number to determine the number of neutrons in the atom's nucleus.
Which of the following statements best compares nuclear power and hydropower based on their rates of renewal?
Hydropower has a faster rate because water is continuously being recycled through the hydrogeological cycle.
Nuclear power has a faster rate because all elements are spontaneously radioactive and are a source of nuclear energy.
Hydropower has a slower rate because a large volume of water vapor that evaporates takes several years to return to water cycle.
Nuclear power has a slower rate because the nuclear waste produced is not radioactive and thus cannot be used further as a fuel.
Hydropower is best compared to nuclear power based on their rates of renewal.
Because water is continually regenerated through the hydrogeological cycle, hydropower has a higher rate.Because all elements spontaneously produce radioactive material, which is a source of nuclear energy, nuclear power has a higher rate.Because it takes a significant amount of evaporated water several years to return to the water cycle, hydropower has a slower rate.Because the nuclear waste generated by nuclear power cannot be recycled as fuel and is not radioactive, it produces waste at a slower pace.What is hydropower's primary source?Water in motion generates hydroelectricity, namely the winter and spring runoff from mountain streams and crystal-clear lakes. Water can be utilized to turn turbines and generators that produce power when it is falling due to gravity.To learn more about hydropower visit:
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a solution with a ph of 11.7 is how many time more basic than a solution with a ph of 8.7
Answer:
1000
Explanation:
A solution with a pH of 11.7 is ____ times more basic (alkaline) than a solution with a pH of 8.7 1000
A scientist is trying to discover information about an unknown metal in a compound. The formula for the compound is believed to be XBr3 where X is the unknown metal. The scientist determined that a 4.727 g sample of this compound contains 5.317×10−2 mol Br . Calculate the atomic mass of the unknown metal, X .
Atomic Mass=
What is the identity of the metal? Provide the name or symbol of the element.
Metal:
The atomic mass of the element X is 56 and the element can be seen to be iron.
What is the identity of element X?In this problem, we are given a compound to obtain the identity of the unknown element therein.
We already can relate that;
Number of moles = mass/molar mass
Number of moles Br = 0.04806 moles
Molar mass of Br could be obtained as 79.9 g/mol
We have;
Mass = Number of moles x molar mass
= 0.04806x 79.9
= 3.84 g
Mass of X = 4.735 - 3.84
= 0.895 g
Given that there are 3 moles of Br for every 1 mole of X. We have 0.04806 mole of Br present in 4.735 g, then the number of moles of X present would be:
0.04806/3 = 0.01602 moles
Molar mass = mass/mole
= 0.895/0.01602
= 55.87 or 56 g/mol
Hence, the element X is iron
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What is the molar mass of 56.75 g of gas exerting a pressure of 2.87 atm on the walls of a 5.29 L container at 230 K
Molar mass is thus 70.6 g/mol.
We must first determine how many moles of gas are there in the container.
PV = nRT
where;
P - pressure = 290 802.75 Pa = 2.87 atm x 101 325 Pa/atm
Volume: 5.29 x 103 m3, or V.
quantity of moles, n
R, the global gas constant, is 8.314 Jmol K-1.
Temperature is 230 K, or T.
using these values as a substitute in the equation
n x 8.314 Jmol 1 K x 230 K = 290 802.75 Pa x 5.29 x 10 3 m3
n = 0.804 mol
the molar mass = [tex]\frac{mass present}{number of moles}[/tex]
the molar mass of gas =[tex]\frac{56.75g}{0.804 mol}[/tex]
therefore molar mass is 70.6 g/mol
Molar mass is 70.6 g/mol as a result.
The molar mass of a chemical compound is defined as the mass of the sample divided by the amount, or the number of moles, in the sample, measured in moles. A substance's molar mass is a bulk characteristic rather than a molecular one.
The phrases "molecular mass" and "formula mass," which refer to molar mass specifically for molecular compounds, are commonly used interchangeably; nevertheless, the definitions provided by the most trustworthy authorities vary.
The molar mass is the appropriate unit for converting between a substance's mass and quantity in bulk quantities.
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Which of the following elements is most likely to have an oxidation state of
+2?
A. Strontium (Sr)
B. Oxygen (0)
C. Sodium (Na)
D. Chlorine (CI)
The element from the list that is most likely to have an oxidation state of +2 is Strontium (Sr).
What is oxidation state?The oxidation state of an element of an atom refers to the total number of electrons that is gainable or losable in order to form a bond with another atom.
The oxidation state of an atom is also known as its oxidation number.
Strontium with atomic number 38 and electron configuration of [Kr]5[tex]s^2[/tex] has 2 losable electrons in order to form a bond.Oxygen with atomic number 8 and electron configuration of [He] 2s²2p⁴ has 2 gainable electrons in order to form a bond.Chlorine with atomic number 17 and electron configuration of [Ne] 3s²3p⁵ has 1 gainable electron in order to form a bond.Thus, the element that is most likely to have an oxidation state of +2 is Strontium (sr).
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The density of titanium is 4.51 g/cm^3. what is the volume (in cubic inches) of 3.0 lb of titanium?
Anything which deteriorates the quality of air around us is called
A. a gas
B. a molecule
C. a pollutant
D. a component
Answer: The answer is C, a pollutant.
Explanation:
The word pollutant comes from the word pollution, pollution is when a chemical makes the air toxic.
Determine the volume of liquid in the graduated cylinder and report it to the correct number of significant figures.
depends on the graduated cylinder's size and the volume between marks. Generally speaking, you can interpolate (guess) to increase the precision a little beyond the volume markers, but whether it will give you an extra sig fig varies.
For instance, a 10-mL graduated cylinder contains markings every 0.1 mL. Your reading will have two sig figs if you simply use the reading as the nearest marking: 4.5 mL, 9.7 mL, etc. However, you can become a little bit more accurate by interpolating. How close is the liquid level to the halfway point between the markings? exact center? So, instead of 4.5 mL, it is 4.55 mL. Approximately halfway? How much? 4.53 or 4.54.
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Which of the following is a benefit of using a debit card for a purchase?
A. You do not need a pin to withdraw funds or make purchases.
B. You can get cash back.
C. You can share it with friends and family.
D. You can use it as a credit card and pay off your debt on a monthly basis.
Answer: D
Explanation: you can use a debit card for many things besides paying off your debt like avoiding fees and charges, staying accountable for your spending, lower tax payments with credit cards, etc.
If you found the mass of the Styrofoam packing peanuts and bricks and divided their mass by their
volumes, which of these would you find to have a higher density?
By dividing the found mass by volume, the density of the object will be obtained. The density of Styrofoam packing peanuts and bricks are almost similar.
Mass of a substance is the quantity of matter present in the substance. The unit of mass is kg.
A substance's volume is how much room it occupies. The unit of volume is [tex]m^3[/tex].
Density of a substance is the mass of the substance present in the given volume.
Density = Mass / Volume
The unit of density is [tex]kg/m^3[/tex].
Objects made from the same substance have the same density.
The density of Styrofoam packing peanuts is 2.3-2.4 pounds per cubic foot and Styrofoam bricks is 2-3 pounds per cubic foot and hence are similar with a slight difference.
Therefore, the density of Styrofoam packing peanuts and bricks is almost same.
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the boiling point of butane is less that that of hexane because of increase in
Hexane, CH3CH2CH2CH2CH2CH3, has a boiling point of 69ºC, while butane has a boiling point of 0.4ºC. Both molecules are nonpolar. Describe the significant difference between these two substances' boiling points.
Intermolecular attractions are the likely cause of the significant disparity in the boiling points of butane and hexane. Due to its size (molecular weight = 86) and higher number of electrons and nuclei, hexane has stronger and more durable van der Waals forces. With a molecular weight of 58, butane is a smaller molecule with less van der Waals forces.
Hexane has a higher boiling point than butane as a result, while butane has a lower boiling point.
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What frequency corresponds to an absorption line at 527 nm? A. 5.69 x 1014 Hz B. 3.77 x 10¹4 Hz C. 1.76 x 10¹4 Hz D. 6.71 10¹4 Hz
Taking into account the definition of wavelength, frecuency and propagation speed, the correct answer is option A.: The frequency corresponding to an absorption line at 527 nm is 5.69×10¹⁴ Hz
WavelengthWavelength is the minimum distance between two successive points on the wave that are in the same state of vibration. It is expressed in units of length (m).
FrequencyFrequency is the number of vibrations that occur in a unit of time. Its unit is s⁻¹ or hertz (Hz).
Propagation speedThe propagation speed is the speed with which the wave propagates in the medium.
The propagation speed relate the wavelength (λ) and the frequency (f) inversely proportional using the following equation:
v = f×λ
All electromagnetic waves propagate in a vacuum at a constant speed of 3×10⁸ m/s, the speed of light.
Frequency in this caseIn this case, you know:
v= 3×10⁸ m/sf= ?λ= 527 nm= 527×10⁻⁹ m (1 nm= 1×10⁻⁹ m)Replacing in the definition of propagation speed:
3×10⁸ m/s= f× 527×10⁻⁹ m
Solving:
f= 3×10⁸ m/s ÷ 527×10⁻⁹ m
f= 5.69×10¹⁴ Hz
In summary, the correct answer is option A.: The frequency corresponding to an absorption line at 527 nm is 5.69×10¹⁴ Hz
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Can someone tell me how to do this. Also just answer the first one so I can get it
Answer:
it is 3 in a half inches long i hope this helped
The molar mass of water (H₂O) is 18.02 g/mol. Yun has 0.025 mol of H₂O for a laboratory experiment.
How many grams of water does she have?
The amount of water Yun has for experiment is 0.45 gram.
One mole of any substance is equal to the Avogadro number. we can obtain number of moles of any element If it's given mass and molar mass are known.number of moles = given mass / molar massThe proportionality factor that connects the quantity of substance in a sample to the number of constituent particles in that sample is called the Avogadro constant. ( 6.023 × 10²³)Given,
molar mass of water (H₂O) is 18.02 g/mol.
Yun has 0.025 mol of H₂O
we have to find out amount of water she has for her experiment
number of moles of water = given mass of water / molar mass of water
mass of water = number of moles of water × molar mass of water
= 0.025 × 18.02
= 0.45 gram
Therefore, Yun has 0.45 gram of water for experiment.
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what is photosynthesis
Answer:
Photosynthesis is the process by which plants use sunlight, water, and carbon dioxide to create oxygen and energy in the form of sugar.
Answer: Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.
Explanation:
What is the oxidation state of O in NO₂?
OA. +2
OB. -2
O C. O
OD. -4
Answer:
Let it be x
[tex]{ \tt{ (oxidation \: state \: of \: nitrogen) + 2x = overall \: charge}} \\ { \tt{ - 4 - 2 x = 0}} \\ { \tt{2x = - 4}} \\ { \tt{x = - 2}}[/tex]
Why is the percentage of food eaten a good number to use? Explain.
Which of the following is a form of identity fraud?
A. Chipping
B. Skimming
C. Chirping
D. Skipping
Answer:
B. Skimming
Explanation:
Skimming is an electronic method of stealing a victim's credit card number and then using the information to make fraudulent purchases.
what is one of the most common causes of injury in the laboratory
Answer:
Chemical Spilling And Heat burns
Explanation:
One of the most common injurys in science labs is various chemical falling due to carless opening or handling
Heat burns are also evenly matched along with chemical spill this is cuased due to burners being left open or not wearing th eprober equipment to be next to heat
A __________ is an area of land that rises very high above the land around it.
lake
mountain
plain
river
Answer:
Mountain
Explanation:
If 2.96 mL of seawater contains about 7.86×10-14 moles of gold, how many atoms of gold are in that volume of seawater? atoms
The number of atoms of gold in the 2.96 mL of the seawater is 4.73×10¹⁰ atoms
Avogadro's hypothesis1 mole of Gold = 6.02×10²³ atoms
With the above information, we can determine the number of atoms in the seawater. Details below
How to determine the atoms in 7.86×10⁻¹⁴ mole of gold1 mole of Gold = 6.02×10²³ atoms
Therefore,
7.86×10⁻¹⁴ mole of gold = (7.86×10⁻¹⁴ mole × 6.02×10²³ atoms) / 1 mole
7.86×10⁻¹⁴ mole of gold = 4.73×10¹⁰ atoms
Thus, 4.73×10¹⁰ atoms of gold are present in the seawater
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There are only two naturally-occuring stable isotopes of lithium, the masses of which are listed in the table below. Use whatever data you need from the ALEKS Periodic Table to calculate the natural abundance of each isotope and complete the table.
The natural abundance of each isotope of lithium:
For [tex]^{6} Li[/tex] = 7.5%
For [tex]^{7} Li[/tex] = 92.5%
Due to the fact that lithium only has two stable isotopes, it follows that only two isotopes contribute to its average atomic mass.
Then, if we take x the proportional abundance of [tex]^{6} Li[/tex] it is possible to state that the decimal abundance of [tex]^{7} Li[/tex] need to be equivalent to 1−x.
Lithium's typical atomic mass will now be equal to =
avg. Atomic weight Li = Atomic weight of [tex]^{6} Li[/tex]× quantile abundance of [tex]^{6} Li[/tex]+ Atomic weight of [tex]^{7} Li[/tex]× quantile abundance of [tex]^{7} Li[/tex]
Since you are aware that the average atomic mass of lithium is
6.941 you can construct the equation as follows.
6.941 = 6.015 × x + 7.016 × (1-x)
x = 0.075
This is the decimal abundance of [tex]^{6} Li[/tex]. The decimal abundance of [tex]^{7} Li[/tex] is 1 - 0.075 = 0.925.
Percent abundances :
For [tex]^{6} Li[/tex] = 7.5%
For [tex]^{7} Li[/tex] = 92.5%
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what consumer in the food chain is going to have to eat the most food tomeet their energy needs?
Answer:
Secondary consumer
Explanation:
The organism that eats the primary consumer to get the energy is known as the secondary consumer. They are generally meat-eaters—carnivores. Tertiary consumers eat primary consumers and secondary consumers. They are carnivore-eating organisms, like eagles or big fish.
Answer:
the producers will eat the most food