Answers
Answer:
Point (3, 100) shows that 3 years is the half-life and 100 mg is remaining of the radioactive substance.
Explanation:
From the diagram given above,
The original amount of the radioactive substance is 200 mg because at time 0 from the graph, this is the amount (i.e 200 mg) remaining.
At point (3, 100), we can see that 100 mg of radioactive material is remaining. This is exactly half the original amount.
Thus, point (3, 100) shows that 3 years is the half-life and 100 mg is remaining of the radioactive substance.
NOTE: Half-life is simply defined as the time taken for half the original amount of radioactive material to decay.
Related Questions
Help Help plz what meaning of the representative elements.
Answers
WS 3.5 more Lewis structures
Answers
A 0.5242-g sample of a compound known to contain only carbon, hydrogen, and oxygen was burned in oxygen to yield 0.9740 g of CO2 and 0.1994 g of H2O. What is the empirical formula of the compound?
Answers
Answer:
C₃H₃O₂
Explanation:
From the question given above, the following data were obtained:
Mass of compound = 0.5242 g
Mass of CO₂ = 0.9740 g
Mass of H₂O = 0.1994 g
Empirical formula =?
Next, we shall determine the mass of carbon, hydrogen and oxygen present in the compound. This can be obtained as follow:
For carbon, C:
Mass of CO₂ = 0.9740 g
Molar mass of CO₂ = 12 + (16×2)
= 12 + 32 = 44 g/mol
Mass of C = 12/44 × 0.9740
Mass of C = 0.2656 g
For hydrogen, H:
Mass of H₂O = 0.1994 g
Molar mass of H₂O = (2×1) + 16
= 2 + 16 = 18 g/mol
Mass of H = 2/18 × 0.1994
Mass of H = 0.0222 g
For oxygen, O:
Mass of compound = 0.5242 g
Mass of C = 0.2656 g
Mass of H = 0.0222 g
Mass of O =?
Mass of O = (Mass of compound) – (Mass of C + Mass of H)
Mass of O = 0.5242 – (0.2656 + 0.0222)
Mass of O = 0.5242 – 0.2878
Mass of O = 0.2364 g
Finally, we shall determine the empirical formula. This can be obtained as follow:
Mass of C = 0.2656 g
Mass of H = 0.0222 g
Mass of O = 0.2364 g
Divide by their molar mass
C = 0.2656 /12 = 0.0221
H = 0.0222 /1 = 0.0222
O = 0.2364 /16 = 0.0148
Divide by the smallest
C = 0.0221 / 0.0148 = 1.5
H = 0.0222 / 0.0148 = 1.5
O = 0.0148 / 0.0148 = 1
Multiply through by 2 to express in whole number.
C = 1.5 × 2 = 3
H = 1.5 × 2 = 3
O = 1 × 2 = 2
Empirical formula => C₃H₃O₂
In matrix form structure PVC stands for what?
Answers
Answer:
polyvinyl chloride
Explanation:
Which of the following is TRUE if Esys = 260 J?
Answers
Answer:
Both the system and the surroundings are losing 260 J. The system is gaining 260 J, while the surroundings are losing 260 J. Both the system and the surroundings are gaining 260 J. The system is losing 260 J, while the surroundings are gaining 260 J. None of the above is true.
can someone please help!!
Answers
Answer:
1:aerobic
2:anaerobic
3:aerobic
Which of the following wavelengths penetrate earth's atmosphere?
O Microwaves
O Gamma rays
O Radio waves
O X-rays
Answers
Answer:
Radio waves are able to penetate the earth's atmosphere due to their low frequency and long wavelength.
Let me know if this helps!
Consider these compounds:
a. CuCO3
b. ZnS
c. Ni(CN)2
d. Ag2CrO4
Complete the following statements by entering the letter corresponding to the correct compound. Without doing any calculations it is possible to determine that silver carbonate is more soluble than _________ , and silver carbonate is less soluble than ____________. It is not possible to determine whether silver carbonate is more or less soluble than _______________ by simply comparing Ksp values.
Answers
Explanation:
If we compare its solubility products without any calculation then, Magnesium hydroxide is more soluble than compound A and C. Magnesium hydroxide is less soluble than compound D.
- The solubility product of magnesium hydroxide and zinc carbonate is same so it is not possible to determine whether it is more or less soluble than compound B
EASY CHEM, WILL GIVE BRAINLIEST!!
Answers
Hi there!
[tex]\large\boxed{4.04g}[/tex]
To solve, we can use dimensional analysis to convert from molecules to grams.
We must use Avogadro's number (6.02 × 10²³) in converting from molecules to moles.
After converting, multiply by the atomic mass, or grams per mole.
[tex]1.204 * 10^{24} moles *\frac{1 mol}{6.02*10^{23}moles}* \frac{2.02g}{1mol }= 4.04g[/tex]
La
Nd
Pm
Sm
Tb
Но
Er
Tm
Yb
Lu
Ac
Np Pu Am Cm Bk
CH
Es
Fm Md No
100 g of acetic acid (CH, COOH) is dissolved in a 500.0 ml solution. What is the molarity? Report your answer with the
correct number of significant figures
Answers
Answer:
3.34 M
Explanation:
Step 1: Given data
Mass of acetic acid: 100 gVolume of solution (V): 500.0 mL (0.5000 L)Step 2: Calculate the moles of acetic acid
The molar mass of acetic acid is 60.05 g/mol.
100 g × 1 mol/60.05 g = 1.67 mol
Step 3: Calculate the molarity of acetic acid
The molarity is equal to the moles of solute divided by the liters of solution.
M = n/V
M = 1.67 mol/0.5000 L = 3.34 M
Which has the least molecular kinetic energy?
water molecules in ...
A. a cloud
B. the ocean
C. Frozen pond
D. Pot of boiling water
Answers
—Evidence—
•- The other answers tend to move while the frozen pond has no movement therefore it’s the answer.
What is the mass of oxygen gas in a 12.2 L
container at 16.0°C and 8.15 atm?
Answer in units of g.
Answers
Answer:
grams O₂ = 134 grams
Explanation:
PV = nRT => n = PV/RT
P = 8.15atm
V = 12.2 Liters
R = 0.08206L·atm/mol·K
T = 16.0°C + 273 = 289K
n = (8.15atm)(12.2L)/(0.08206L·atm/mol·K)(289K) = 4.2 moles O₂
grams O₂ = 4.2 moles O₂ x 32g/mol = 134 grams O₂
QUICK PLZZZ why do people run away from the hot weather into the cool ocean on a sunny day? Explain your answer using one of the properties of water?
Answers
Am-241 has a half life of roughly 432 years. How much of
a 100 gram sample would remain after 1,296 years?
Answer to the nearest tenth.
Answers
Answer:
12.5 g
Explanation:
From the question given above, the following data were obtained:
Half-life (t½) = 432 years.
Original amount (N₀) = 100 g
Time (t) = 1296 years
Amount remaining (N) =?
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Half-life (t½) = 432 years.
Time (t) = 1296 years
Number of half-lives (n) =?
n = t / t½
n = 1296 / 432
n = 3
Thus, 3 half-lives has elapsed.
Finally, we shall determine the amount of the isotope remaining. This can be obtained as follow:
Original amount (N₀) = 100 g
Number of half-lives (n) = 3
Amount remaining (N) =?
N = 1/2ⁿ × N₀
N = 1/2³ × 100
N = 1/8 × 100
N = 0.125 × 100
N = 12.5 g
Thus, 12.5 g of the isotope is remaining.
100 mL of a 0.300 M solution of AgNO3 reacts with 100 mL of a 0.300 M solution of HCl in a
coffee-cup calorimeter and the temperature rises from 21.80 °C to 23.20 °C. Assuming the density
and specific heat of the resulting solution is 1.00 g/mL and 4.18 J/g. °C, respectfully, what is the
AHºx?
A 39.0 kJ/mol
B +39.0 kJ/mol
C.+1.17 kJ/mol
Answers
Answer:
[tex]\Delta _rH=-39,1kJ[/tex]
Explanation:
Hello!
In this case, since it is possible to assume that the heat released by the reaction is absorbed by the water in the calorimeter we can write:
[tex]Q_{rxn}=-200mL*\frac{1g}{1mL}*4.184\frac{J}{g\°C}*(23.20\°C-21.80\°C)\\\\Q_{rxn}=-1,171.5J[/tex]
Now, since the reaction between silver nitrate and hydrochloric acid is:
[tex]HCl+AgNO_3\rightarrow AgCl+HNO_3[/tex]
We can see there is a reacting 1:1 mole ratio, thus, the reacting moles are computed via the molarity of the solutions:
[tex]n=0.300mol/L*0.100L=0.0300mol[/tex]
Finally, the enthalpy of reaction is:
[tex]\Delta _rH=\frac{-1,171.5J}{0.0300mol}=-39,050.7J[/tex]
And in kJ:
[tex]\Delta _rH=-39,1kJ[/tex]
Best regards!
Which two statements about redox reactions are true?
A. Double-replacement reactions are redox reactions.
B. Acid-base reactions are redox reactions.
C. One type of atom is oxidized and another is reduced.
D. Electrons are transferred from one atom to another.
SUBMIT
Answers
Answer:
C. One type of atom is oxidized and another is reduced
D. Electrons are transferred from one atom to another
Explanation:
just took the test, i hope this helps!!
have a nice day and take care of yourself!! :))
One type of atom is oxidized and another is reduced and Electrons are transferred from one atom to another. Therefore, the correct options are options C,D.
What is redox reaction?Any chemical process in which a participating chemical species' oxidation number changes is known as an oxidation-reduction reaction, often known as a redox reaction. The phrase refers to a broad range of processes. Numerous oxidation-reduction processes are as frequent and well-known as fire, metal corrosion and disintegration, fruit browning, respiration, and photosynthesis—basic life processes.
The combined processes of oxidation and reduction are known as redox reactions due to their complimentary nature. The oxidising agent is the reactant that causes the oxidation, while the reducing agent itself reduces this reagent. One type of atom is oxidized and another is reduced and Electrons are transferred from one atom to another.
Therefore, the correct options are options C,D.
To know more about redox reaction, here:
https://brainly.com/question/13293425
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What is the age of a bone that emits radiation from carbon-14 at the rate of 0.96
decays/min/g?
Answers
Does anyone know how to do this
Answers
Answer:
Explanation:
1-butanol has 4 carbon atoms with an OH group at the first carbon atom.
Dichlorodifluoromethane has 1 carbon atom with 2 chlorine atoms and 2 fluorine atoms.
how partition of Bengal mobilize
please help me
Answers
what type of energy is playing the piano
A.light
B. Thermal
C.electrical
D.mechanical
E.sound
Answers
Answer:
E sound
Explanation:
Kayla is creating a model to show her understanding of the water cycle. She wants to show that water is constantly cycling between the atmosphere and Earth’s surface.
What would be the BEST type of model for Kayla to create.
A 3-D model of H2O created with gumdrops and toothpicks.
A. A diagram of molecules gaining energy as they being to evaporate and enter the atmosphere.
B. A poster with pictures of lakes, oceans, rivers and ponds.
C. A circular diagram with arrows showing the movement of water between Earth’s surface and atmosphere.
Answers
Answer:C
Explanation:
It would be the most visually understandable.It would be easyer to understand what you are modeling.
Convert to moles 12.06 x 10^22 molecules
Answers
Answer:
0.2 mole
Explanation:
From the question given above, the following data were obtained:
Number of molecules = 12.06×10²²
Number of mole =?
From Avogadro's hypothesis,
6.02×10²³ molecules = 1 mole
Therefore,
12.06×10²² molecules = 12.06×10²² / 6.02×10²³
12.06×10²² molecules = 0.2 mole
Thus, 12.06×10²² molecules is equivalent to 0.2 mole
Do all living things depend on nonliving things to survive? Support your answer with an example.
Answers
Answer:
Living things need nonliving things to survive. Without food, water, and air, living things die. Sunlight, shelter, and soil are also important for living things. ... Plants use water from the soil, carbon dioxide from the air, and energy from sunlight to make their own food.
Explanation:
Answer: yes they do here are is an example a tree depends on water to keep it hydrated.
Explanation:
What can wind energy be transformed or converted into?
Answers
Answer:
Electrical energy
Explanation:
The wind Mill is an example of a device that converts wind energy into electrical energy
NASA helps fund science education
Answers
Answer:
What are the options
Explanation:
Answer:
"People with more knowledge of science are always healthier"
Explanation:
Which product forms from a reaction between calcium (Ca) and phosphorus
(P)?
A. Ca2P3
B. Cap
C. CazP2
D. CaP2
Answers
Among these options, the correct formula for calcium phosphide is D. [tex]CaP_2[/tex]. Option D
The product formed from a reaction between calcium (Ca) and phosphorus (P) is calcium phosphide, which is represented by the chemical formula [tex]Ca_3P_2[/tex].
In the reaction between calcium and phosphorus, the calcium atom (Ca) donates two electrons to each phosphorus atom (P). This results in the formation of calcium ions (Ca2+) and phosphide ions (P3-). The ions combine to form the compound calcium phosphide ([tex]Ca_3P_2[/tex]).
The formula [tex]Ca_3P_2[/tex]indicates that three calcium atoms combine with two phosphorus atoms. The numerical subscripts are determined by the charges of the ions involved. Calcium, being a group 2 element, forms ions with a +2 charge (Ca2+), while phosphorus, being a group 15 element, forms ions with a -3 charge (P3-).
The product options provided are:
A. [tex]Ca_3P_2[/tex]
B. Cap
C. [tex]CazP_2[/tex]
D. [tex]CaP_2[/tex]
Among these options, the correct formula for calcium phosphide is D. [tex]CaP_2[/tex].
For more such questions on calcium phosphide visit:
https://brainly.com/question/4023397
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Answer: Ca3P2
This is the answer!
Explanation:
A. Ca3P2
B. CaP2
C. Ca2P3
D. CaP
If 10 grams of NaHCO3 react with an excess of HCl, what would be the theoretical mass of NaCl produced?
Worth 15 points. I will give brainliest for best answer. Thank you.
Answers
Answer:
Explanation:Reaction NaHCO3 + HCl ⇒ NaCl + H2O + CO2
Molar mass M = (22.99+1.008+ 12.01+3·16 ) g/mol. Calculate
Amount of substance n =m/M, n(NaCl) is equal.
M(NaCl) = 58.44 g/mol and mass m= n·M
When a large rock falls down a slope and breaks into small pieces, this is called _____________ _______________.
Group of answer choices
Answers
Answer: Mechanical weathering
Explanation:
Mechanical weathering breaks rocks into smaller pieces
A salt with a high melting point can be obtained from reaction between metal and
acid solution. The metal that used in this reaction is iron and the acid solution is
hydrochloric acid.
a. What is the chemical name of salt above?
Answers
Iron (II) chloride and hydrogen gas
Chemical name:
FeCl2 (aq) + H2 (g)
You are presented with a white solid and told that, because of careless labeling, it is not clear whether the substance is mercury(I) nitrate, calcium carbonate, or aluminum nitrate. When you transfer the solid to a beaker and add water, the solid dissolves to give a clear solution. Next, a Na2SO4(aq) solution is added and a white precipitate forms.
Required:
a. What is the identity of the unknown white solid?
b. How many grams of CH3OH must be added to water to prepare 150 mL of a solution that is 2.5 M CH3OH?
Answers
Answer:
aluminum nitrate
Explanation:
We already know that calcium carbonate is insoluble in water hence it will not even dissolve in the water.
Mercury(I) nitrate is soluble in water, when sodium sulfate (Na2SO4) is added to mercury(I) nitrate (Hg2(NO3)2), a pale yellow precipitate is formed.
Aluminum nitrate is soluble in water and reacts with Na2SO4(aq) solution according to the reaction, 2Al(NO3)3(aq)+3Na2SO4(aq) ---> Al2(SO4)3(s)+6NaNO3(aq). The precipitate, Al2(SO4)3(s) is a white crystalline hygroscopic solid.