Answer:
6.25 gram
Explanation:
Applying,
R = R'([tex]2^{a/n}[/tex])................ Equation 1
Where R = Original mass of the isotope, R' = mass of the isotope left after disintegration, a = Total time, n = half life.
make R' the subject of the equation
R' = R/([tex]2^{a/n}[/tex])................. Equation 2
From the question,
Given: R = 100 gram, a = 20 munites, n = 5 minutes.
Substitute these values into equation 2
R' = 100/([tex]2^{20/5}[/tex])
R' = 100/[tex]2^{4}[/tex]
R' = 100/16
R' = 6.25 gram
Una determinada cantidad de neón ocupa 0,5 litros (L) a 200ºC. Calcular el volumen que ocuparía a 0ºC si la presión se mantiene constante. Recuerda que la temperatura la debes transformar a K (grados Kelvin), y para ello se suma °C + 273.
Answer:
[tex]V_2=0.87L[/tex]
Explanation:
¡Hola!
En este caso, al considerar la información dada, inferimos que este problem se resuelve aplicando la ley de Charles, dado que tenemos una relación entre el volume y la temperatura:
[tex]\frac{V_2}{T_2}=\frac{V_1}{T_1}[/tex]
Así, despejamos V2 (volumen final) y obtenemos:
[tex]V_2=\frac{V_1T_2}{T_1}\\\\V_2=\frac{0.5L*473.15K}{273.15K}\\\\V_2=0.87L[/tex]
Saludos!
Define Acid and alkalis
Answer:
Acids have a pH less than 7. Acids contain lots of hydrogen ions
Alkalis have a pH greater than 7. Alkalis contain lots of hydroxide ions
Please mark as brainliest if answer is right
Have a great day, be safe and healthy
Thank u
XD
Answer:
ACID - A substance with particular chemical properties including turning litmus red, neutralizing alkalis, and dissolving some metals; typically, a corrosive or sour-tasting liquid of this kind. Often contrasted with alkali and base.
ALKALIS - A compound with particular chemical properties including turning litmus blue and neutralizing or effervescing with acids; typically, a caustic or corrosive substance of this kind such as lime or soda: Often contrasted with acid and base.
Hope this helps
A lead mass is heated and placed in a foam cup caloriemeter containing 40.0mL of water at 17.0 C. The water reaches a temperature of 20.0 C. How many joules of heat were released by the lead?
the Answer is 502 Joules
A student was in the lab testing the conductivity of different solutions. Three of the solutions were NaNO3, Ca(NO3)2, and Al(NO3)3. Which of the solutions should be the best conductor of electricity?
Answer:
Aluminium nitrate
Explanation:
[tex]Al(NO _{3}) _{3}[/tex]
This is because there are many conducting nitrate ions compared to the other electrolytes
Which force was the first to be discovered?
Gravity
Weak nuclear force
Strong nuclear force
Electromagnetic force
Answer:
Gravity
Explanation:
Sir Isaac Newton was an English mathematician and mathematician and physicist who lived from 1642-1727. The legend is that Newton discovered Gravity when he saw a falling apple while thinking about the forces of nature.
Answer:
A. Gravity
Explanation:
because Isaac Newton published a comprehensive theory of gravity in 1687. Though others had thought about it before him, Newton was the first to create a theory that applied to all objects, large and small, using mathematics that was ahead of its time.
PLS HELP ASAP NO LINKS
What type of scientist studies matter and its composition?
Biologist
Chemist
Physicist
Engineer
Answer:
.biology and maybe physics
Answer:
Biologist
ExplanationBiologist Unlike the above type of scientist, geoscientists’ work involves exploring the earth and its internal environment. They study the composition, structure, and processes of the earth by being indoors and outdoors. They contribute to the discovery of mines, petroleum deposits, minerals, and other aspects of the earth.
What is the molarity of 40ml of NaOH if it takes 25ml of 0.5 molar HCl to neutralize it?
Answer:
Molarity of 40 ml of NaoH is 0.3125 mL
Explanation:
As we know
Molarity of acid * volume of acid = molarity of base * volume of base
Substituting the given values, we get
[tex]0.5 * 25 = X* 40 \\X = \frac{0.5*25}{40} \\X = 0.3125[/tex]
Molarity of 40 ml of NaoH is 0.3125 mL
Dropping leaves in the fall is a characteristic of what type of tree?
A; deciduous
B; evergreen
C; coniferous
D; boreal
Answer:
A; deciduous
Explanation:
Trees that lose all of their leaves for part of the year are known as deciduous trees. Those that don't are called evergreen trees. Common deciduous trees in the Northern Hemisphere include several species of ash, aspen, beech, birch, cherry, elm, hickory, hornbeam, maple, oak, poplar and willow
Answer:
the answer is decidous trees
How much energy is required to change 75 grams of copper at 35 degrees Celsius
to liquid copper at 1200 degrees C?
34950 J of energy is required to change 75 grams of copper at 35 degrees Celsius to liquid copper at 1200 degrees Celsius.
What is Specific Heat?The specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius.
It is a measure of how much energy it takes to raise the temperature of a substance. It is the amount of heat necessary to raise one mass unit of that substance by one temperature unit.
It is given by the formula -
Q = mcΔT
where, Q = amount of heat
m = mass
c = specific heat
ΔT = Change in temperature
Given,
Mass of copper = 75g
ΔT = ( 1200 - 35) = 1165⁰C
c = 0.4 J/g ⁰C
Q = mcΔT
= 75 × 0.4 × 1165
= 34950 J
Therefore, 34950 J of energy is required to change 75 grams of copper at 35 degrees Celsius to liquid copper at 1200 degrees Celsius.
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help me please guys #9
Answer:
Bases
Explanation:
Most soaps fall under the base category as they are slippery and will taste bitter if you taste it (DONT TRY IT THO).
As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution?
A) Decreases
B) Increases
C) Remains the same
B) increasesAnswer:
Explanation:
As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution increases. Therefore, the correct option is option B.
What is mole?The World System representing Units (SI) uses a mole (symbol mol) as the unit of material amount. How many fundamental entities of a particular substance are present in an object and sample is determined by the quantity of that material. An elementary entity can be a single atom, a molecule, a pair of ions, an ion pair, even a subatomic particle like a proton depending on the makeup of the substance.
For instance, although having differing volumes and masses, ten molecules of liquid (a chemical compound) because 10 moles of mercurial (a chemical element) both have the same quantity of substance, because the mercury has exactly one atom every every molecular structure of the water. As the concentration of a KOH solution increases, the number of moles of HCl needed to neutralize the KOH solution.
Therefore, the correct option is option B.
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What is important in order for a radioisotope to provide accurate dating
results?
O A. The half-life should be similar to the age of the object.
B. The radioisotope cannot be part of a decay chain.
O C. The isotope must undergo transmutation.
O D. The item being dated must be very old.
The most important factor to be considered in order for a radioisotope to provide accurate dating simply is:
The half-life should be similar to the age of the object.
The correct answer choice is option a.
Why half-life should be similar to the age of the object in determining accurate dating of a radioisotope.Half-life of radioisotope helps in determining dating accurately simply because it helps to predict the amount of radioactive substance remaining after a given period of time.
In conclusion, it can be perfectly deduced from the explanation given above that the half-life of a radioisotope usually, frequently and most of the time helps to determine the rate at which these substances decay.
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Select the correct answer.
A circuit is used in which process?
OA. electricity
OB. magnetism
OC. velocity
OD. gravity
Answer:
electricity
Explanation:
A circuit is used in every electrical and electronics operation.
What is the enthalpy of reaction for the decomposition of calcium carbonate?
CaCO3(s) Right arrow. CaO(s) + CO2(g)
A 2-column table with 6 rows. Column 1 is labeled Compound with entries upper C a upper O solid, Upper C a upper C upper O subscript 3 solid, Upper C subscript 6 upper H subscript 6 gas, Upper C upper O subscript 2 gas, Upper H subscript 2 upper O gas, Upper N upper O subscript 2 gas. Column 2 is labeled Delta H subscript f in kilojoules per molecule with entries negative 157.3, negative 1,207.1, 82.90, negative 393.5, negative 241.82, 33.84.
Answer:
First Blank: 656.3 kJ
Second Blank: Endothermic
Explanation:
Edge 21'
Answer:
1. 656.3
2. endothermic
Explanation:
After a drought in which all the cotton crops died, a farmer moves away. Which of the following best describes the order of growth if the farm is left abandoned?
a
Cotton --> shrubs --> tall grasses --> weeds
b
Lichen --> flowers --> shrubs --> weeds
c
Lichen --> shrubs --> weeds --> flowers
d
Weeds --> tall grasses --> shrubs --> trees
6. Calculate the new pressure in atm if 2.45 L of a gas at a pressure of 1.20 atm is contracted to a new
volume of 2.20 L
Answer:
[tex]\boxed {\boxed {\sf x \approx 1.34 \ atm}}[/tex]
Explanation:
Since we are dealing with temperature and pressure, we must use Boyle's Law. This states that the pressure is inversely proportional to the volume. The formula is:
[tex]P_1V_1=P_2V_2[/tex]
Where P is the pressure and V is the volume.
We know the original pressure (P₁) of the gas is 1.20 atmospheres and the volume (V₁) is 2.45 liters.
[tex]1.20 \ atm * 2.45 \ L = P_2V_2[/tex]
We also know the gas is contracted to a new volume of 2.20 liters (V₂) , but we do not know the pressure (P₂). We can use x.
[tex]1.20 \ atm *2.45 \ L = x * 2.20 \ L[/tex]
We can solve the left side of the equation and multiply.
[tex]2.94 \ atm *L= x*2.20 \ L[/tex]
We are trying to find the new pressure (x), so we must isolate the variable. It is being multiplied by 2.20 liters. The inverse of multiplication is division, so we divide both sides by 2.20 L.
[tex]\frac {2.94 \ atm *L}{2.20 \ L}=\frac{x*2.20 \ L}{2.20 \ L}[/tex]
[tex]\frac {2.94 \ atm *L}{2.20 \ L}=x[/tex]
The units of liters cancel.
[tex]\frac {2.94 \ atm}{2.20 \ }=x[/tex]
[tex]1.33636363636 \ atm =x[/tex]
The original measurements have 3 significant figures, so our answer should have the same. For the number we found, that is the hundredth place.
The 6 in the thousandth place tells us to leave the 3 in the hundredth place.
[tex]1.34 \ atm \approx x[/tex]
The new pressure is approximately 1.34 atmospheres.
Beryllium hydrogen carbonate is more than 3% hydrogen by mass.
True
False
what will litmus paper turn when it reacts with sodium nitrate?
What volume of hydrogen sulfide gas will be collected if
39.0 grams of sodium sulfide are reacted?
Answer:
yes
Explanation:
Answer:
578.....882...767..86
The solid dissolves quickly is a chemical or physical reaction
Answer:
i think it is chemical wait no physical
Explanation:
The first organisms to arrive in an ecosystem?
How many formula units are in 325 grams of iron (III) chloride?
Answer:
1.204 × 10^24 formula units
Explanation:
Using the following formula to convert mass of iron (III) chloride to moles;
mole = mass/molar mass
Molar mass of FeCl3 = 56 + 35.5(3)
= 56 + 106.5
= 162.5g/mol
Mole = 325/162.5
mole = 2mol
Next, to calculate the formula units of FeCl3, we multiply the number of moles of FeCl3 by Avagadro number (6.02 × 10^23)
Formula units of FeCl3 = 2 × 6.02 × 10^23
12.04 × 10^23
= 1.204 × 10^24 formula units.
Convert 4.00 atm to mmHg
Group of answer choices
404 mmHg
2430 mmHg
.746 mmHg
3040 mmHg
Answer:
3040 mmHg
Explanation:
Here
we have to convert 4.00 atm to mmHg
As we know that
The number of atm in 1 mmHg is 0.0013157895567935
Now there is 4.00 atm So, in mmHg it would be
And, according to this, the working is given below:
= 4 ÷ 0.0013157895567935
= 3,039.99
= 3040 mmHg
Hence, the last option is correct
And, the same is relevant and considered too
If you stay at 90 degrees Celsius and a gas in a liquid solution has a pressure of 2 atm, what solubility should it have if it has a solubility of 64 g/L at a pressure of 8 atm?
Answer:
im not sure
Explanation:
Name the following alkyne.
Please help me <3
Answer:
D. 7-methyl-3-octyne
Explanation:
1) Identify the parent chain and name it like an alkane.
• The longest chain of carbons, which consists of the functional group (which is the alkyne group in this case: C≡C).
• There are 8 carbons in the longest chain, so it is called an octane.
2) Now, identify the location of the functional group.
• The location number of the functional group should be as low as possible. Thus although we could count from the right, we start counting from the left since the functional group is closer to the left. From the left, the functional group would be at carbon 8 while from the left, it is on carbon 3.
• Replace 'ane' with 'yne' in octane for the alkyne group.
• This would give us 3-octyne.
3) Lastly, add in the name of the branch.
• Here we have one branch, -CH₃. This is read as methyl.
• Identify the location number of the branch by counting the number of carbons in the same direction as when we counted the location number of the functional group. The methyl branch has a location number of 7.
• Adding the name of the branch before the parent chain, we would arrive at 7-methyl-3-octyne as the IUPAC name of the alkyne.
Further Explanation:
A) This option is incorrect as there are only 8 carbons in the parent chain. Although there are 9 carbons in total, the 9th carbon is taken care of in '7-methyl'.
B) Location number of the functional group should be as low as possible, so start counting the number of carbons from the left!
C) Since the functional group is an alkyne, the word 'octane' should be 'octyne' instead.
6) What is the picture below an example of?
Answer:
The picture below is an example of a food chain.
Explanation:
The bug (can't tell which one by the picture) eats the grass, the frog eats the bug, the snake eats the frog, and the eagle eats the snake.
Draw Conclusions does the F2 generation support that lack of wings is a genetic trait? Explain why or why not
Answer:
An F1 offspring could produce four types of gametes, RY, Ry, rY, and ry. The F2 generation supports the independent-assortment model and refutes the linkage model.
Explanation:
Find the molarity of 4.18 g MgCI2 in 500mL of water
Answer:
The molarity of MgCl₂ in water is 0.088 mol/L.
Explanation:
The molarity of MgCl₂ can be calculated as follows:
[tex] C = \frac{\eta}{V} = \frac{m}{MV} [/tex]
Where:
C: is the molarity =?
η: is the number of moles of MgCl₂ = m/M
V: is the volume of water = 500 mL = 0.500 L
m: is the mass of MgCl₂ = 4.18 g
M: is the molar mass of MgCl₂ = 95.211 g/mol
Hence, the molarity is:
[tex] C = \frac{m}{MV} = \frac{4.18 g}{95.211 g/mol*0.500 L} = 0.088 mol/L [/tex]
Therefore, the molarity of MgCl₂ in water is 0.088 mol/L.
I hope it helps you!
6)
Which formula can represent
an
alkyne?
A)
C₃H6
B)
C₂H4
C)
C3H4
D)
C₂H6
Answer:
c)C3H4
Explanation:
Answer: C. C3H4
Explanation:
I got it wrong and castle learning showed me the answer
Two glass rods are rubbed together. One of the glass rods are brought near (but
does not touch) an uncharged pith ball. Would you expect the pith ball to attract,
repel, or do nothing? Explain why.
Answer:
Do Nothing
Explanation:
Charges are transferred by friction when two different types of bodies are rubbed together. This is known as charging by friction.
However, when two materials of the same type are rubbed together, no charge is transferred from one object to the other hence there is no transfer of charges by friction and none of the two glass rods are charged.
Therefore, when one of the glass rods is brought close but does not touch the pith ball, nothing happens.