Answer:
Half-life = 28.8 years
Explanation:
The radioactive decay of an atom follows the equation:
Ln[A] = -kt + ln[A]₀
Where [A] is actual amount of isotope after time t; k is decay constant and [A]₀ initial amount of isotope
Solving for k:
Ln[0.393g] = -k*10yrs + ln[0.500]
-0.2408 = -k*10yrs
0.02408yrs⁻¹ = k
Half-life, is:
Half-life = ln 2 / k
Half-life = ln 2 / 0.02408yrs⁻¹
Half-life = 28.8 years
The isotope [tex]38Sr^{90}[/tex] is one of the extremely hazardous species in the residues from nuclear power generation. The strontium in a 0.500-g sample diminishes to 0.393 g in 10.0 yrs, the half-life is - 28.78
Formula:
radioactive decay follows first-order kinetics,
k = [tex]\frac{1}{t}ln\frac{a}{x}[/tex]
Given:
a = initial amount = 0.5 g
x = amount of isomer after 10 years = 0.393 g
t= time = 10 years
Solution:
k = [tex]\frac{1}{10}ln\frac{0.5}{0.393}[/tex]
= 0.02408
k = [tex]\frac{0.693}{t/2}[/tex]
T(1/2) = half-life time
= [tex]\frac{0.693}{k}[/tex]
= [tex]\frac{0.693}{0.02408}[/tex]
= 28.78 years.
Thus, The isotope [tex]38Sr^{90}[/tex] is one of the extremely hazardous species in the residues from nuclear power generation. The strontium in a 0.500-g sample diminishes to 0.393 g in 10.0 yrs, the half-life is - 28.78
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Which manufacturing process is shown in the photograph?
O A. Forming
B. Combining
C. Conditioning
D. Separating
Answer:
c
Explanation:
im being timed
someone pls help
i have 3 minutes
1.) Name a metal and explain how the physical properties of this raw metal help change it into common household items?
2.)What is one chemical property Rb and Cu have in common?
4. The type of thermal energy transfer that heats our homes is called
Answer:
conduction is the answer
to multiply food with the help of a simple machine
Answer:
Explanation:
Inclined Plane: Easy Lifting. An inclined plane is simply an even, sloping surface. ...
Wedge: Splitting and Separating. ...
Screw: Fastening and Moving. ...
Lever: Multiplying Force. ...
Wheel and Axle: Rolling. ...
Pulley: Hoisting Heavy Loads. ...
Scissors: Making the Cut. ...
Hand Truck: Mover's Friend.
How many Chorine atoms should bond with one Aluminum atom?
Answer:
three chlorine atoms
Explanation:
18 gram of sucrose is dissolved in 180 gram of water. Calculate the number of oxygen atoms in the solution.
answer: 6.684×10^24
We know, molecular mass of sucrose is 342 g/mol.
So, number of moles in 18 g is :
[tex]n_1 = \dfrac{342\ g/mol}{18\ g}\\\\n_1 = 0.053 \ moles[/tex]
Also, number of moles of water is :
[tex]n_2 = \dfrac{180}{18} \\\\n_2 = 10 \ moles[/tex]
We know, 1 mole of sucrose contain 11 moles of oxygen.
So,
[tex]n' = 0.053\times 11\\\\n'= 0.583\ moles[/tex]
1 mole of water contain 1 mole of oxygen .
So, moles of oxygen in water are :
[tex]n'' = 10\ moles[/tex]
Total number of moles, [tex]n' + n'' = 10.583 \ moles[/tex] .
Number of oxygen atoms are :
[tex]N = 6.022 \times 10^{23}\times 10.583\\\\N = 6.37 \times 10^{24}[/tex]
Hence, this is the required solution.
define the term "filtration"
Answer:
the action or process of filtering something. hope this helps :D
How can you increase an object's kinetic energy?
Hydrogen ions _____.
are hydrogen atoms which have lost protons
are released by bases
have positive charges
have negative charges
are hydrogen atoms which have lost protons
Which property of metals makes them good conductors of heat
Answer:
the molecules are tightly bound together, making it easy for electric currents to jump from one molecule to the next.
Explanation:
Answer:
They are good conductors of thermal energy because their delocalised electrons transfer energy. The close packing of the metal ions in the lattice. the delocalised electrons can carry kinetic energy through the lattice.
Explanation:
4. Two bulbs have a resistance of 20 ohms when working normally. They are placed in a series
circuit whey they operate normally. What is the combined resistance of the two bulbs?
(1 Point)
22 ohms
20 ohms
10 ohms
40 ohms
Answer:
R = 40 ohms
Explanation:
Two bulbs have a resistance of 20 ohms when working normally.
When they are placed in series, the combined resistance is given by :
R = R₁ + R₂
We have, R₁ = R₂ = 20 ohms
R = 20 +20
= 40 ohms
Hence, the combined resistance of the two bulbs is 40 ohms.
I need help with life in a pond?
4. A sample of gas has a pressure of 700 mmHg and 30.0°C. Ar what temperature would the pressure be 600 mmHg if the volume remains constant?
Answer:
T₂ = 259.84 K
T₂ = -13.31 °C
Explanation:
Given data:
Initial pressure = 700 mmHg
Initial temperature = 30.0°C (30+273.15 K = 303.15 K)
Final temperature = ?
Final pressure = 600 mmHg
Solution:
According to Gay-Lussac Law,
The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.
Mathematical relationship:
P₁/T₁ = P₂/T₂
Now we will put the values in formula:
700 mmHg /303.15 K = 600 mmHg / T₂
T₂ = 600 mmHg × 303.15 K / 700 mmHg
T₂ =181890 mmHg.K /700 mmHg
T₂ = 259.84 K
Temperature in celsius
259.84 K - 273.15 = -13.31 °C
pls helppp
37.9 grams of unknown substance undergoes a temperature increase of 25.0°C after absorbing 989 J. What is the specific heat of the substance?
The specific heat of the substance : c = 1.044 J/g °C J/g °C
Further explanationGiven
Heat absorbed by substance = 989 J
m = mass = 37.9 g
Δt = Temperature difference : 25 °C
Required
The specific heat
Solution
Heat can be formulated
Q = m.c.Δt
Input the value :
989 = 37.9 x c x 25
c = 989 : (37.9 x 25)
c = 1.044 J/g °C
Which of the following is an example of a mixture?
A. Ca
B. CO2 + H2 + O2
C. NaCl
D. C6H12O6
The first one to help me will get the brainliest and 50 points UwU
Answer:
B is because their not combined
Answer:
tru it's B
Explanation:
give the person above me brainliest if u want
The law of conservation of matter states that matter is neither created nor destroyed in a chemical reaction. Which of the following must be true? *
A the mass of the products is greater than the mass of the reactants
B the mass of the products is less than the mass of the reactants
C the mass of the reactants must equal the mass of the products
Answer:
A
Explanation:
help plzzzzzzzzzzzzzzz
Answer:
Blue is the metal Metals react by losing electrons from the outermost shell, which means their outermost electrons and now closer to the nucleus (one shell lower) and thus they get smaller when you go from metal atom to metal ion.
Explanation:
Can somebody plz help answer this science questions (only 1-2 sentences is good thx !
WILL MARK BRAINLIEST WHOEVER ANSWERS FIRST!…promise :D
Is water wet? This is a discussion for easy points so I suggest you answer it.
Answer:
Water isn't wet by itself but it makes other materials wet. Like paper, clothes, shoes, etc.
Explanation:
Help please What would you do if your water was turned off? Where or how would you get water for you
and your family? Be specific, realistic, and creative on your answer.
Answer:
If the water was turned off i would go look for some in a river and filter it out and bring for my family too.
Explain:
A small portion of the periodic table of the elements is reproduced here showing eight elements and the groups to which they belong.
Based on its position on the periodic table, which column of elements would be most likely to chemically combine with lithium in 2:1 ratio?
it is 2.1 that it is his w ga hshshwu
How does a thermometer measure temperature?
Ari dissolves 1 gram of sugar in 10 grams of water. What will be the mass of the dissolved sugar and water ? Explain your answer.
Answer:
the answer would be 11 grams of water/sugar water
Explanation: its that because 11 grams plus 1 gram = 11 grams
even though it may seem it may just go away that mass has to go somewhere it just doesn't vanish from the earth.
Graduated cylinder is filled to 41.5mL with water, and a price of granite is placed in the cylinder displacing the level to 47.6mL. What is the volume of the granite piece in cubic centimeters
Answer:
6.1 cm³
Explanation:
To solve this problem we first need to keep in mind Archimedes' principle:
The volume of water (or any fluid) displaced by a submerged object is equal to the object's volume.With that in mind we calculate the volume of the granite piece in mililiters:
Volume displaced = 47.6 mL - 41.5 mL = 6.1 mLVolume of the granite piece = 6.1 mLGiven that one cubic centimeter is equal to one mililiter, the volume of the granite piece in cm³ is 6.1 cm³.
Please write down the definitions of elements, compounds, mixtures, homogenous mixtures, and heterogenous mixtures.
When heat from the sun turns water into water vapor this is called?
A) condensation
B) runoff
C) precipitation
D) evaporation
A reptile egg is shown in the diagram.
Y
Which best describes the function of the structure
labeled Y?
O food source
O protection
waste collection
gas exchange
HELP
Answer:Its D
Explanation:
Trust
Answer:
food source
Explanation:
Got 100%
Organisms can be classified as
and
Answer:
Eukaryotes and prokaryotes
Explanation:
HELP ME PLEASE: The image at the left shows three stars in the constellation Orion: Betelgeuse (A), Mintaka (B), and Rigel (C). How do the appearances of stars A, B, and C compare?
Answer:
B and C look blue therefore they are hot but A and C look big
The appearance of the three stars is compared by their colors and sizes.
In the image you can see the stars of the constellation Orion.
The star Betelgeuse (A) looks yellow and large (perhaps because of its closeness).The star Mintaka (B) is small (perhaps further away) and blue in color.The star Rigel (C) looks big and blue.According to the above, it can be inferred that the three stars differ in their colors and sizes. Their colors can be determined by the chemical composition of them, while their sizes by the distance that separates them from the Earth, making the farthest ones look smaller and the closest ones, bigger.
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S
SIO₂ +3C Sic +20o
Sic ? mass in grams
С c-
Answer:
26.74g
Explanation:
The equation of the reaction is;
SIO₂ + 3C --> SiC +2CO
From the balanced equation, the relationship between SiC and C is;
3 mol of C produces 1 mol of SiC
Converting mol to mass using; Mass = moles * Molar mass
Mass of SiC = 1 mol * 40.11 g/mol = 40.11g
This means;
3 mol of C produces 40.11g of SiC
2 mol of C produces xg of SiC
3 = 40.11
2 = x
x = 2 * 40.11 / 3 = 26.74g