Answer:
I-131- To treat goitre
U- 238- To produce electricity
(ii) (ii) and (iii)
Explanation:
Radioisotopes have various applications in science. These applications may be positive or negative.
I-131- is used to treat goitre. This is a very important medical application of this isotope of iodine.
U-238 is ordinarily non-fissile but can be transformed to Pu-239 and used as a nuclear fuel for electricity generation.
A scientific ________ must have a control, so that the variables that could affect the out come is reduced. A:experiment B:conclusion. C:investigation. D:reasoning
Answer:
A.experiment
Explanation:
hope this helps
Help!!!!!!!!!!!!!!!!!!
The density of the sample : 0.827 g/L
Further explanationIn general, the gas equation can be written
[tex]\large {\boxed {\bold {PV = nRT}}}[/tex]
where
P = pressure, atm , N/m²
V = volume, liter
n = number of moles
R = gas constant = 0.082 l.atm / mol K (P= atm, v= liter),or 8,314 J/mol K (P=Pa or N/m2, v= m³)
T = temperature, Kelvin
n= 1 mol
MW Neon = 20,1797 g/mol
mass of Neon :
[tex]\tt mass=mol\times MW\\\\mass=1\times 20,1797 =20.1797~g[/tex]
The density of the sample :
[tex]\tt \rho=\dfrac{m}{V}\\\\\rho=\dfrac{20,1797}{24.4}=0.827~g/L[/tex]
or We can use the ideal gas formula ta find density :
[tex]\tt \rho=\dfrac{P\times MW}{RT}\\\\\rho=\dfrac{1\times 20.1797}{0.082\times 298}\\\\\rho=0.826~g/L[/tex]
What goes in photosynthesis and what comes out of photosynthesis?
Answer:
Carbon dioxide goes in and oxogen comes out
P.S. Sunlight needed for this process to work
Explanation:
Can somebody that is good at science help me with these two questions? Please and thank you!
How many moles are in 1.81 x 1024 molecules of CO2?
Answer:
3.01 molesExplanation:
To find the number of moles in a substance given it's number of entities we use the formula
[tex]n = \frac{N}{L} \\[/tex]
where n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question we have
[tex]n = \frac{1.81 \times {10}^{24} }{6.02 \times {10}^{23} } \\ = 3.006644...[/tex]
We have the final answer as
3.01 molesHope this helps you
21 III
Choose the geologic formation that fits the description: rocks are stretched, moved
vertically into blocks, and dropped; the lower blocks are called graben and the taller
blocks called horst.
O volcanic mountains
O ocean ridges
O fault block mountains
folded mountains
Answer:
Lifted fault block mountains
Explanation:
Above which temperature does the thermal conductivity of water start to fall?
Answer:
It’s actually 130 degrees Celsius.
Explanation:
What are three physical properties that could be used to identify gold?
Answer:
solid ,hard, not see through
Explanation:
Answer:
There are many properties out there, so three include bright yellow color, luster shine, and the maleability that determines the durability.
in which group on the periodic table does the atom pictures belong?
a) 4
b) 6
c) 16
d) 14
Answer: Group 14
Explanation:
It's a carbon atom with 4 valance electrons.
What are two reasons that someone would want to become a scientist?
1 point
Your answer
Electromagnetic radiation at its maximum wavelength is _____.
A. Radio waves
B. Infrared
C. X rays
D. None of the above
Answer:
Option A) Radio waves.
Explanation:
Have a great day.
25.0cm3 of s saturated potassium hydroxide is neutralized by 35.0cm3 of hydrogen chloride acid of concentration 0.75 mol/dm3. Calculate the concentration of potassium hydroxide solution. Please help, will give brainliest, unhelpful answers will get reported.
Answer:
Concentration of the original [tex]\rm KOH[/tex] solution: approximately [tex]1.05\; \rm mol \cdot dm^{-3}[/tex].
Explanation:
Notice that the concentration of the [tex]\rm HCl[/tex] solution is in the unit [tex]\rm mol\cdot dm^{-3}[/tex]. However, the unit of the two volumes is [tex]\rm cm^{3}[/tex]. Convert the unit of the two volumes to [tex]\rm dm^{3}[/tex] to match the unit of concentration.
[tex]\begin{aligned} V(\mathrm{NaOH}) &= 25.0\; \rm cm^{3} \\ &= 25.0\; \rm cm^{3} \times \frac{1\; \rm dm^{3}}{1000\; \rm cm^{3}} \approx 0.0250\; \rm dm^{3} \end{aligned}[/tex].
[tex]\begin{aligned} V(\mathrm{HCl}) &= 35.0\; \rm cm^{3} \\ &= 35.0\; \rm cm^{3} \times \frac{1\; \rm dm^{3}}{1000\; \rm cm^{3}} \approx 0.0350\; \rm dm^{3} \end{aligned}[/tex].
Calculate the number of moles of [tex]\rm HCl[/tex] molecules in that [tex]0.0350\; \rm dm^{3}[/tex] of [tex]0.75\; \rm mol \cdot dm^{3}[/tex] [tex]\rm HCl\![/tex] solution:
[tex]\begin{aligned}n(\mathrm{HCl}) &= c(\mathrm{HCl}) \cdot V(\mathrm{HCl}) \\ &= 0.00350\; \rm dm^{3} \times 0.75\; \rm mol \cdot dm^{3} \\ &\approx 0.02625\; \rm mol\end{aligned}[/tex].
[tex]\rm HCl[/tex] is a monoprotic acid. In other words, each [tex]\rm HCl\![/tex] would release up to one proton [tex]\rm H^{+}[/tex].
On the other hand, [tex]\rm KOH[/tex] is a monoprotic base. Each [tex]\rm KOH\![/tex] formula unit would react with up to one [tex]\rm H^{+}[/tex].
Hence, [tex]\rm HCl[/tex] molecules and [tex]\rm KOH\![/tex] formula units would react at a one-to-one ratio.
[tex]{\rm HCl}\, (aq) + {\rm NaOH}\, (aq) \to {\rm NaCl}\, (aq) + {\rm H_2O}\, (l)[/tex].
Therefore, that [tex]0.02625\; \rm mol[/tex] of [tex]\rm HCl[/tex] molecules would neutralize exactly the same number of [tex]\rm NaOH[/tex] formula units. That is: [tex]n(\mathrm{NaOH}) = 0.02625\; \rm mol[/tex].
Calculate the concentration of a [tex]\rm NaOH[/tex] solution where [tex]V(\mathrm{NaOH}) = 0.0250\; \rm dm^{3}[/tex] and [tex]n(\mathrm{NaOH}) = 0.02625\; \rm mol[/tex]:
[tex]\begin{aligned}c(\mathrm{NaOH}) &= \frac{n(\mathrm{NaOH})}{V(\mathrm{NaOH})} \\ &= \frac{0.02625\; \rm mol}{0.0250\; \rm dm^{3}}\approx 1.05\; \rm mol \cdot dm^{-3}\end{aligned}[/tex].
Which Ion has the same electron configuration as an Ar atom
1. Cl -
2. F -
3. Li+
4. Na +
*WILL GIVE A BRAINIEST & 15 POINTS TO THE CORRECT ANSWER*
When an electron falls back to its original shell, the electron will...
A.) absorb energy as it goes to the excited state
B.) absorb energy as it goes to the ground state
C.) release energy as it goes to the excited state
D.) release energy as it goes to the ground state
Answer: D
Explanation:
true or false: Some fungi are unicellular and some fungi are multicellular
Answer:
True
Explanation:
This reaction type occurs when different atoms in two different compounds trade places.
A) synthesis
B) decomposition
C) double replacement
D) single replacement
Double replacement is the reaction that typically occurs when different atoms in two different compounds trade places (Option C).
What is double-replacement?Double-replacement is a class of chemical reaction where two atoms can exchange their places to generate new combinations.
This type of chemical reaction (double-replacement reaction) is very common in nature.In conclusion, double replacement is the reaction that typically occurs when different atoms in two different compounds trade places (Option C).
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How many more valence electrons does this atom need to fulfill the Octet
Rule?
Answer:
In the valence shell, it should have 8 valence electrons.
Explanation:
Isomers are molecules with the same molecular formula, but different structural formulae.
How many isomers are there in C7H16?
A.6
B.7
C.8
D.9
Answer:
D 9 is the answer
Explanation:
Hope it helps you
Please mark as brainliest answerWhat is the difference between elements and compounds? *
which elements are cations and anions
Lithium
Sodium
Beryllium
aluminum
phosphorus
oxygen
fluorine
Answer:
Lithium,sodium, beryllium, aluminum form cations and the rest form anions
Explanation:
i think the question should be rephrased as 'which elements form cations".
1. 2KCIO3, -- 2KCI + 302
How many moles of O2 will be produced from 2.25 moles of KCIO3?
Answer:
3.375moles of O₂
Explanation:
The reaction expression is given as;
2KClO₃ → 2KCl + 3O₂
Number of moles of KClO₃ = 2.25moles
Now;
To find the number of moles of O₂ produced we use known number of moles.
So;
2 mole of KClO₃ will produce 3 moles of O₂
2.25moles of KClO₃ will produce [tex]\frac{2.25 x 3}{2}[/tex] = 3.375moles of O₂
Similarities between sliding and fluid friction
If you have 23mg of water, at what temperature will it Boil?
Answer:
i believe it is in the 200
Explanation:
What is the speed of an object that covers 10 miles in 5 hours?
a. 5 mph
b. 15 mph
c. 2 mph
d. 50 mph
Answer:
2 miles per hour.
Explanation:
10/5=2
To solve this we must be knowing each and every concept related to speed and its calculations. Therefore, the correct option is option C.
What is speed?Speed may be defined as the distance traveled by an item in the amount of time it requires to travel that distance. In other words, it measures how rapidly an item travels but does not provide direction.
The Scientific unit system is most typically used to express speed. Speed is determined in metres per second, or m/s, since distance is recorded in metres while time is recorded in seconds.
Mathematically,
speed= distance/ time
distance= 10 miles
time= 5 hours
substituting all the given values in the above equation, we get
speed=10/5
on calculations, we get
speed = 2 mph
Therefore, the correct option is option C.
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WHATS THE DIFFERENCE BETWEEN MASS AND WEIGHT WELPPPPP
Answer:
Mass is amount of matter. Weight is how that matter is affected by gravity.
Explanation:
Girls are usually completely physically mature by _____ years old.
A.
17
B.
19
C.
14
D.
21
Please select the best answer from the choices provided. Anyone know for EDGE
A
B
C
D
Answer:
a 17 bc it is how it works
Girls are usually completely physically mature by 18 years old.
What is puberty ?Puberty refers to the physical transformation of a child's body into an adult one capable of fertile reproduction.
In girls puberty generally attains before two years earlier than the boys. And the exact age of the girls to attain puberty is in between the age of 10 to 14.
Hence the age of girls to attain puberty is 14.
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how many protons does Beryllium have?
Answer:
4
Explanation:
its a rare element, usually occurring as a product of the spallation of larger nuclei that have collided with cosmic rays
Use what you know about endothermic and exothermic reactions to explain the differences in the graphs above
Answer:
yes I do
But I can't see the question very well
Explanation:
the amount of energy required to move an electron
Answer:
quantum of energy
Fill in the blanks using terms from this unit.
Even though plants are rooted in the ground, they still move, exert
Blank Options
choose your answer...
and do
Blank Options
choose your answer...
.
Plant cells have very strong cell walls that allow
Blank Options
choose your answer...
to build up inside of the cell as water is absorbed. This pressure is called
Blank Options
choose your answer...
.
When turgor pressure is high enough in a cell, the cell walls become
Blank Options
choose your answer...
and As a result, the cell becomes rigid and the plant is able to stand
Blank Options
choose your answer...
and straight. When a plant does not get enough water, the turgor pressure inside of the cells
Blank Options
choose your answer...
.
A decrease in pushing against the cell wall causes the cells to lose their
Blank Options
choose your answer...
and This causes the plant to begin to droop, or
Blank Options
choose your answer...
.
When the wilted plant gets enough water, the cells will become rigid again, and the plant will stand firm and straight once again.
Answer:
Even though plants are rooted in the ground, they still move, exert force, and do work.
Plant cells have very strong cell walls that allow pressure to build up inside of the cell as water is absorbed. This pressure is called turgor.
When turgor pressure is high enough in a cell, the cell walls become firm and as a result, the cell becomes rigid and the plant is able to stand tall and straight.
When a plant does not get enough water, the turgor pressure inside of the cells decreases. A decrease in pressure pushing against the cell wall causes the cells to lose their shape and shrink. This causes the plant to begin to droop or wilt.
When the wilted plant gets enough water, the cells will become rigid again, and the plant will stand firm and straight once again.
Explanation: