Answers
Answer:
a1
The main difference between SPECT and PET scans is the type of radiotracers used. While SPECT scans measure gamma rays, the decay of the radiotracers used with PET scans produce small particles called positrons. A positron is a particle with roughly the same mass as an electron but oppositely charged.
Explanation:
a2
While imaging tests such as X-rays can show what the structures inside your body look like, a SPECT scan produces images that show how your organs work. For instance, a SPECT scan can show how blood flows to your heart or what areas of your brain are more active or less active.
a3
PET and SPECT have been extensively evaluated as diagnostic procedures for dementia. Substantial progress has been made in developing radioligands that bind to amyloid deposits in the brain, which should provide new opportunities for early diagnosis and treatment monitoring in Alzheimer's disease
a4
What are the disadvantages of spect as compared to pet?
However, SPECT has issues, including long scan times and low-resolution images prone to artifacts and attenuation. Some artifacts can easily be misidentified as perfusion defects. SPECT also does not provide a quantifiable estimate of the blood flow, whereas PET does, experts say.
Related Questions
Which is an example of an object increasing its kinetic energy
Question 3 options:
an airplane after landing on a level runway.
a rocket before launch.
a train stopped at the station.
a mouse running faster after spotting a cat.
Answers
Answer:
The answer to this question is the A choice. A rocket before launch.
Explanation:
In the definition of kinetic energy, it says: In physics, the kinetic energy of an object is the energy that it possesses due to its motion. It is defined as the work needed to accelerate a body of a given mass from rest to its stated velocity. Having gained this energy during its acceleration, the body maintains this kinetic energy unless its speed changes.
Which phrase accurately describes the location of Africa? O mostly in the eastern hemisphere mostly south of the Tropic of Capricorn O borders the Pacific Ocean O lies north of Europe
Answers
Answer:
mostly in the eastern hemisphere mostly south of the Tropic of Capricorn
Explanation:
The statement which best describes the location of Africa is that it is found
mostly in the eastern hemisphere.
Africa is a continent which comprises of countries such as Nigeria, Ghana,
Kenya etc. It is bounded on the north by the tropic of cancer and towards
the south of the tropic of capricorn.
Africa also lies in the eastern hemisphere and is found to the south of the
European continent.
Read more on https://brainly.com/question/24201145
evanrosario11 avatar
evanrosario11
7 minutes ago
Physics
High School
100 Points + Brainlest PLZ HElP
What ion would each of the following elements form?
For example, a sodium atom (Na) will form a sodium ion (Na+1). You will need to list the charge of the ion. You will need to list the charge of the ion for the seven questions below.
1. Beryllium (Be)
2. Sulfur (S)
3. Potassium (K)
4. Aluminum (Al)
5. Bromine (Br)
6. Oxygen (O)
7. Magnesium (Mg)
Answers
Answer:
Forming positive ions
Explanation:
A sodium atom has one electron in its outer shell. ... It will still have 11 positive protons but only 10 negative electrons. So, the overall charge is +1. A positive sign is added to the symbol for sodium, Na +.
Hope it helps
xoxo
Explanation:
Forming Positive Ions
Hope It Helped U
What happens when a virus becomes latent?
Answers
Answer:
the full viral genome is retained in the host cell, but its expression is dramatically restricted, such that few viral antigens and no viral particles are produced.
Explanation:
Can farmers simply plant more acres of crops to feed a growing population?
Answers
Answer:
I believe they can if it's a small town/village
Explanation:
Kate wrote the steps of the carbon cycle to describe how carbon is cycled through specific organisms. The steps are in random order.
1 - The rabbit decomposes.
2 - The rabbit eats the carrot plant.
3 - The carrot plant takes in carbon dioxide from the air during photosynthesis.
4 - Carbon compounds are returned to the soil.
Which lists the steps in order?
2, 3, 1, 4
3, 2, 1, 4
3, 4, 2, 1
2, 4, 3, 1
Answers
3, 2, 1, 4
Further explanation:The process of photosynthesis is the process of converting carbon dioxide and water into energy in the form of carbohydrates using sunlight. Usually done by plants that have leafy za called chlorophyll.
Carbohydrates themselves are formed from the C-carbon, H-hydrogen and O-oxygen components
Rabbit food is carrots that contain carbohydrates, which are part of the photosynthesis process
3. The carrot plant takes in carbon dioxide from the air during photosynthesis.
Reaction
6CO₂ + 6H₂O ⇒ C₆H₁₂O₆ + 6O₂
2. The rabbit eats the carrot plant.
Rabbits meet their carbohydrate source for energy by eating carrots
1. The rabbit decomposes.
Rabbits in time will experience a process of decomposition
4 - Carbon compounds are returned to the soil.
The carbon content in rabbits will also be decomposed into the soil again
Answer:
3,2,1,4
Explanation:
Q. Explain why is sulfuric acid a corrosive?
.
.
.
.
.
.
Can we clean a dumb humans brain with windex?if yes then tell me how?
Answers
Answer: yes
Explanation: cut open their head and spray their head with windex. THAT SIMPLE
Rubidium is a soft, silvery-white metal that has two common isotopes, 85Rb and 87Rb. If the abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, what is the average atomic mass of Rubidium?
Answers
The average atomic mass of Rubidium : 85.226 u
Further explanationIsotopes are atoms whose no-atom has the same number of protons while still having a different number of neutrons.
So Isotopes are elements that have the same Atomic Number (Proton)
Atomic mass is the average atomic mass of all its isotopes
In determining the mass of an atom, as a standard is the mass of 1 carbon-12 atom whose mass is 12 amu
Mass atom X = mass isotope 1 . % + mass isotope 2.%
The abundance of 85Rb is 80% and the abundance of 87Rb is 19.8%, so the average atomic mass of Rubidium :
[tex]\tt the~average~atomic~mass=0.8\times 85+0.198\times 87\\\\the~average~atomic~mass=\boxed{\bold{85.226~u}}[/tex]
How many more valence electrons does this atom need to fulfill the Octet
Rule? (Urgent need help)
Answers
Answer: The octet rule is a bonding theory used to predict the molecular structure of covalently bonded molecules. According to the rule, atoms seek to have eight electrons in their outer—or valence—electron shells. Each atom will share, gain, or lose electrons to fill these outer electron shells with exactly eight electrons.
Explanation:
You have a shiny metal disc that weighs 1.31 kg that you want to find out what its made of. When you put the disc into a graduated cylinder with 5L in it, you see that the water level rose by about 125 mL. You have a list of densities for various shiny metals: silver= 10.5 g/ mL, nickel= 8.9 g/mL, titanium = 4.5 g/mL, and rhodium = 10.7 g/ mL. What is the disc made of?
Answers
Answer:
The disc is made of silver.
Explanation:
To solve this question we need to calculate the metal's density. To do so we need its mass (already given by the problem, 1.31 kg) and its volume.
Following Archimedes' principle, the volume of water displaced by the disk is equal to the disk's volume. This means the metal's volume is 125 mL.
Now we convert 1.31 kg into g, to better compare with the given options:
1.31 kg * 1000 = 1310 gFinally we calculate the metal's density:
Density = Mass / VolumeDensity = 1310 g / 125 mL = 10.48 g/mLLooking at the densities given by the problem, the closest one is silver.
How many moles of Mg(OH)2 will react with 2.5 mol HCI?
Answers
Answer:
1.25mole of Mg(OH)₂
Explanation:
The reaction is between Mg(OH)₂ and HCl, this is a neutralization reaction between an acid and a base.
Mg(OH)₂ + 2HCl → MgCl₂ + 2H₂O
The balanced reaction equation is given above.
2 mole of HCl reacts with 1 mole of Mg(OH)₂
So, 2.5mole of HCl will react with [tex]\frac{2.5}{2}[/tex] = 1.25mole of Mg(OH)₂
The number of moles of Mg(OH)₂ is given as 1.25mol
a ball with a mass of 20 kg is accelerating at 4 m/s/s while being thrown . about how much force was used to throw the ball
Answers
Answer:
80 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × acceleration
From the question we have
force = 20 × 4
We have the final answer as
80 NHope this helps you
Answer:
80 n
Hope I helped
Anyone know the answer
Answers
Answer:
a and d
Explanation:
a bromine and the calcium atom loses two elections
How many grams are in 7.5 moles of C6H12?
Group of answer choices
0.09g
630g
11.2
84g
Answers
Answer:
630gC₆H₁₂
Explanation:
How many grams are in 7.5 moles of C₆H₁₂?
C₆:12.011×6=72.066
H₁₂:1.008×12=12.096
72.066+12.096=84.162
84.162g/mol C₆H₁₂
7.5 molC₆H₁₂ ×84.162g/molC₆H₁₂= 631.215gC₆H₁₂
how many atoms are in a sample of uranium with a mass of 789 g.
Answers
Number of atoms : 1.996 x 10²⁴
Further explanationThe mole is the number of particles(molecules, atoms, ions) contained in a substance
1 mol = 6.02.10²³ particles
Can be formulated
N=n x No
N = number of particles
n = mol
No = Avogadro's = 6.02.10²³
mol of Uranium with mass=789 g (Ar U=238,02891 u) :
[tex]\tt mol=\dfrac{mass}{Ar}\\\\mol=\dfrac{789}{238,02891 u}\\\\mol=3.315[/tex]
Number of atoms :
[tex]\tt N=3.315\times 6.02\times 10^{23}\\\\N=1.996\times 10^{24}~atoms[/tex]
if u know that answer i will mark has brainliest
Answers
Answer:
The clear liquid is less dense than the black liquid, which is why it floats on top. If the volume were different, you would visually see more clear liquid than black and vice versa.
The clear liquid is less dense than the black liquid
Answer:
A. The clear liquid is less dense than the black liquid
Explanation:
Since the clear liquid since on top of the black one it's density is less. Whatever liquid has a higher density will sink to the bottom of the flask.
Explain why the following structure is incorrect
Answers
Answer:
there is too many electrons around the shell
Explanation:
Oxygen has to bond to two other atoms so the C-O bond should be a double bond to fulfil both of their bonding rules.
Hydrogen can only bond to one other atom, therefore it cannot make a double bond so that bond must be a single bond. (Carbon there is also bonding to five atoms so changing it to a single bond will fulfil both of their bonding rules).
An oxide of arsenic contains 3.26 g of arsenic and 1.04 g of oxygen. What is the empirical formula for this oxide?
Answers
The empirical formula for this oxide : As₂O₃
Further explanation:
Given
mass of Arsenic=3.26 g
mass of Oxygen = 1.04 g
Required
The empirical formula
Analysis
find mole of elementsdetermine the ratio of each elementSolution
mol of Arsenic(MW=74,9216 u) :
[tex]\tt mol=\dfrac{3.26}{74,9216}=0.0435[/tex]
mol of Oxygen(MW=15.999 u) :
[tex]\tt mol=\dfrac{1.04}{15.999}=0.065[/tex].
The ratio for each element (divide by smaller mol⇒Arsenic)
Arsenic : Oxygen :
[tex]\tt \dfrac{0.0435}{0.0435}\div \dfrac{0.065}{0.0435}=1\div 1.5\rightarrow 2\div 3[/tex]
The empirical formula : As₂O₃
How much work is required to pull a sled if you use 60J of work in 5 seconds?
Answers
Answer:
DO I Look Like santa too you how am i supposed to know How about this how about you goo.gle the answer wow smart
Explanation:
What are ionic compounds
Answers
. Classify each of the organisms in Figures 2 and 3 as
herbivore, carnivore, or omnivore. Explain your
classifications.
HELLLPPPP MEEEE PLEASE
Answers
Answer:
Herbivore, Omnivore & Carnivore
Explanation:
Herbivore they eat grass, Omnivores eat fruits and vegetables & Carnivores eat meat or flesh so that's why herb then omni and last carni bc so omni and herbi eat like the same thing
Answer:
Herbivore, Omnivore & Carnivore
Explanation:
Which best explains how convection affects the atmosphere
Answers
Answer:
The heating of the Earth's surface and atmosphere by the sun drives convection within the atmosphere and ocean. This convection produces winds and ocean currents. The greater the pressure differences between a low-pressure area and a high-pressure area, the stronger the winds
in which of the following is the symbol for the ion and the number of electrons it contains given correctly? *
Answers
Answer:Number of electrons that are present in an atom is determined by the electronic configuration of that atom.
If an ion is carrying a positive charge, it means that the atom has lost electrons and if an ion is carrying a negative charge, it means that the atom has gained electrons.
For the given options:
Option A: The atomic number of hydrogen atom is 1 and the electronic configuration for ion will be:
Thus, this atom does not have any electrons.
Option B: The atomic number of bromine atom is 35 and the electronic configuration for ion will be:
Thus, this atom has 36 electrons.
Option C: The atomic number of aluminium atom is 13 and the electronic configuration for ion will be:
Explanation:
How many atoms of S are in the following formula: 3Na(SO4)2
1) 6
2) 8
3) 3
4) 5
Answers
Answer:
6
Explanation:
a + c = r solve for a
Answers
Answer: A = -c + r
Explanation:
Answer:
a = r-c. its that simple I guess
What type of reaction is this?
Zn + K2 CrO 4 --> K + ZnCro4
A) single replacement
B) double replacement
C) decomposition
D) synthesis
Answers
Answer:
a) single replacment........................
What is different about the transition metals and
their charges from other groups on the periodic
table?
A: Their charge is positive but not always the same each
time
B: Their charge is negative but not always the same each
time
C: they are usually neutral
Answers
Answer:
i think a im not 100 %sure
Explanation:
Most transition metals differ from the metals of Groups 1, 2, and 13 in that they are capable of forming more than one cation with different ionic charges. It can sometimes lose two electrons to form the Fe2+ ion, while at other times it loses three electrons to form the Fe3+ i hope it helped
WILL GIVE BRAINLIEST (major help!!! need now!!!) David observed properties of four different compounds, only one of which is an ionic compound. His observations are shown in the chart.
A 2-column table with 4 rows. The first column labeled compound has entries W, X, Y, Z. The second column labeled observations has entries is a hard solid, melts at 44 degrees C, has a molecular structure; is a brittle solid, does not conduct electricity in water, has a crystal structure; is a hard solid, conducts electricity, has a molecular structure; is a brittle solid, melts at 801 degrees C, has a crystal structure.
Which is most likely the ionic compound?
W
X
Y
Z
Answers
Answer:I think it’s y sorry if I’m wrong
Explanation:
Answer:
i think it might be y
Explanation:
what does an atomic emission spectrum look like if the electrons energy levels in an atom were not quantizied
a. lines would be shifted into the ultraviole region
b. there would be fewer lines
c. there will be more lines
d. the spectrum would be constnuous
Answers
Answer: The spectrum would be continuous
Explanation:
Atomic transitions allow us to find that the correct answer to what would happen if there was no quantization is:
d. the spectrum would be continous
In the models of atoms the correct explanation for the energy was given by Planck, by establishing that the energy of an electron is:
E = h ν
Where E is the energy, h the Planck constant and ν the frequency.
Therefore a transition occurs as the jump of an electron from one level to another
ΔE = E₂ - E₁
In all atomic models the levels are discrete, so the jumps are also discrete.
If the levels were continuous, the energy difference between the lines disappears and we have a continuous emission spectrum.
Let's review the different answers:
a. False. The lines disappear
b. False. This for if the separation between levels increases, which is the opposite process to the one analyzed.
c. False. The lines disappear
d) True. The spectrum is a continuum without any separation.
In conclusion, using the atomic transitions we find that the correct answer for what would happen if there was no quantization is:
d. the spectrum would be constnuous
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What is the concentration of a stock solution if 20 mL was used to make 400 mL of a 1.44
M solution?
30 M
40 M
50 M
5M
Answers
Given :
Volume of stock solution, [tex]V_s = 20\ mL[/tex].
Volume of diluted solution, [tex]V_d = 400 \ mL[/tex].
Molarity of diluted solution, [tex]M_d = 1.44\ M[/tex].
To Find :
The concentration of the stock solution.
Solution :
We know, dilution factor is given by :
[tex]D.F=\dfrac{V_ {diluted}}{V_{stock}}[/tex] ....1)
and [tex]D.F= \dfrac{M_{stock}}{M_{diluted}}[/tex] ....2)
Putting volume in above equation, we get :
D.F = 400/20
D.F = 20
Putting value of D.F in equation 2) we get :
[tex]\dfrac{M_{stock}}{M_{diluted}} = 20\\\\M_{stock} = 20\times 1.44\\\\M_{stock} =28.8\ M[/tex]
The concentration of stock solution is nearest to 30 M.
Therefore, the correct option is 1) 30 M.
