Fluorine-21 has a half life of approximately 12 seconds. What fraction of the original nuclei would remain after 1 minute?
Answer:
The correct answer would be = 1/32.
Explanation:
The half-life is the time required for a quantity to reduce to half of the initial value of an object or element.
it is given that Fluorine-21 has a half-life time = 12 seconds
then in a minute the number of half-lives,
12 seconds = 12/60 of a minute or 1/5 of a minute
This means in 1 minute we will half the sample 5 times.
(1/2)^5 = 1/32 is the fractional remainder
Thus, the correct answer would be 1/32.
The pressure in a tire is 101 kPa at 10.0°C, what will be the pressure of a tire at 45.0°C?
Answer:
P₂ = 113.49 kPa
Explanation:
Given that,
Initial pressure, P₁ = 101 kPa
Initial temperature, T₁ = 10.0°C = 283 K
Final temperature, T₂ = 45°C = 318 K
The relation between pressure and temperature is given by :
[tex]\dfrac{P_1}{T_1}=\dfrac{P_2}{T_2}[/tex]
Where
P₂ is the new pressure
So,
[tex]P_2=\dfrac{P_1T_2}{T_1}\\\\P_2=\dfrac{101 \times 318}{283 }\\\\P_2=113.49\ kPa[/tex]
So, the new pressure is equal to 113.49 kPa.
Calculemos la formula empirica y molecular de carbonato de hierro Fe2(co3)3.Fe.38.3%C.12.3%.0.4 92% masa 292g
Respuesta:
292 g / mol;
Por favor, consulte la explicación.
Explicación:
El número de átomos de cada elemento en el compuesto: Fe2 (co3) 3.
Fe = 2; C = 3; 0 = 3 * 3 = 9
Fe2 = 112 g / mol
C = 12 g / mol
O = 16 g /
Masa molecular = ((112 + (12 * 3) + (16 * 9)
= (112 + 36 + 144)
= 292 g / mol.
Total = 2 + 3 + 9 = 14
Fe2 = 112/292 * 100% = 38,356%
C = 36/292 * 100% = 12,328 * '
O = (16 * 9) / 292 * 100% = 49,32%
Pls 50 points right answer gets brainliest
Explain the meaning of thermal energy transfer and give specific examples of conduction, convection, and radiation.
Answer:
Thermal energy transfer involves the transfer of internal energy. The three types of thermal energy transfer are conduction, convection and radiation. ... Those are both good examples of convection, the movement of warm particles from warmer to cooler locations, Conduction is the transfer of thermal energy through direct contact. Convection is the transfer of thermal energy through the movement of a liquid or gas. Radiation is the transfer of thermal energy through thermal emission.
Explanation:
Hope this helps!
Answer:
thermal energy: the part of total internal energy that can be transferred (a portion of the kinetic energy)
heat is the thermal energy that flows from one substance to another due to a temperature difference.
Thermal energy is measured in temperature change.
Thermal energy transfer stops when thermal equilibrium is achieved (Both substances at the same temperature).
conduction: Transfer of thermal energy through a solid object like heat transferring up a metal spoon from a hot cup of coffee.
convection: the transfer of thermal energy due to the movement of a liquid or gas caused by differences in temperature. Only in a fluid (liquid or gas). Breezes, ocean currents.
radiation: Transfer energy with or without matter. Warming from the Sun, microwave oven.
4. How can acids and bases behave in terms of electrolytes/reactivity?
Answer:
Strong acids are strong electrolytes. Such acids ionize completely.
Weak acids and bases are weak electrolytes. Such bases and acids ionize only to a small extent.
Explanation:
Electrolytes are the substances that produce ions when they are dissolved in water. Electrolytes can be categorized as bases, acids, and salts.
Strong acids are strong electrolytes. Such acids ionize completely.
Weak acids and bases are weak electrolytes. Such bases and acids ionize only to a small extent.
How many moles are present in 29.4g of Aluminum (AI)? *
Answer:
588 mole
29.4
+29.4
5 8. 8g
A 55 kg person on Earth has the __________mass on the moon.
Answer:
89.1 N
Explanation:
W = m gm = 55.0 x 1.62 = 89.1 N
what compound does hydrogen form?
How many moles of nitrogen (N2) gas are required to react with 9.00 moles of hydrogen (H2) gas?
Answer: 6 MOLES
Explanation:
40 g of NaCl is added to 1500 g of water. What is the molality of the resulting
solution?
Molality = moles of solute/mass (in kg) of solvent
The solute here is NaCl, of which you have 40 g or 40/58.4428 = 0.6844 moles NaCl.
The solvent here is water, of which you have 1500 g or 1.500 kg H2O.
The molality of the resulting solution would thus be 0.6844 moles NaCl/1.500 kg H2O = 0.4562 mol/kg.
If you have to consider sig figs, then your final answer would have one sig fig (40 g has one sig fig). In that case, your final answer would be 0.5 mol/kg.
For the balanced equation shown below, how many moles of H2O will react with 9 moles of N2?
N2 + 4H2O --> 2H2O2 + N2H4
Answer:
36 mole of H20
Explanation:
N2 + 4H2O --> 2H2O2 + N2H4
H20 : N2
4 : 1
x : 9
cross multiplication
so,
= 9x4/1 = 36 mole of H20
I hope this helps a little bit.
Identify the gas from it calculated molar mass. P = 103.2 kPa V = 225 mL T = 25.00 *C m= 0.375 g N2 Ar CO2 Kr O2 H2 Og Xe H2O He Ne
Answer:
Not sure yet but I will get back
Explanation:
what is the main function of photosynthesis
Answer:
to provide food to the plant also known as glucose
A rock sample from the moon includes a mineral that contains small amounts of the radioactive isotope Potassium-40 and its daughter element Argon-40 (half-life of 1.3 billion years). This mineral would not form with any Argon-40. Consider a crystal with 7 atoms of Argon-40 for every 1 atom of Potassium-40. How many atoms of Potassium-40 were present when the crystal formed for each atom of Potassium-40 that exists today
Answer:
There were originally 8 atoms of Potassium-40.
Explanation:
The half-life of a radioactive material is the time taken for half the original material to decay or the time required for a quantity of the radioactive substance to reduce to half of its initial value.
If the original material formed without any Argon-40, it means that the atoms originally present were Potassium-40 atoms.
Presently, there are 7 Argon-40 atoms for every 1 of Potassium-40, we can deduce the number of half-lifes the Potassium-40 has undergone as follows :
After one half-life, (1/2) there will be one Potassium-40 atom for every Argon-40 atom.
After a second half life, 1/2 × 1/2 = 1/4: there will be one Potassium-40 atom for every three atoms of Argon-40.
After a third half-life, 1/4 × 1/2 = 1/8: there will be one Potassium-40 atom for every 7 atoms of Argon-40.
Since there are 1/8 atoms of Potassium-40 presently, there were originally 8 atoms of Potassium-40.
Hello, can anyone help me with this question?
Answer: a. [tex]11.9\times 10^{23}atoms[/tex] of carbon
b. [tex]35.7\times 10^{23}atoms[/tex] of hydrogen
c. [tex]5.96\times 10^{23}atoms[/tex] of oxygen
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text {Molar Mass}}=\frac{45.6g}{46.07g/mol}=0.989moles[/tex]
a) 1 mole of ethanol [tex](C_2H_5OH)[/tex] contains = [tex]2\times 6.023\times 10^{23}=12.05\times 10^{23}atoms[/tex] of carbon
Thus 0.989 moles ethanol [tex](C_2H_5OH)[/tex] contains = [tex]\frac{12.05\times 10^{23}}{1}\times 0.989=11.9\times 10^{23}atoms[/tex] of carbon
b) 1 mole of ethanol [tex](C_2H_5OH)[/tex] contains = [tex]6\times 6.023\times 10^{23}=36.14\times 10^{23}atoms[/tex] of hydrogen
Thus 0.989 moles ethanol [tex](C_2H_5OH)[/tex] contains = [tex]\frac{36.14\times 10^{23}}{1}\times 0.989=35.7\times 10^{23}atoms[/tex] of hydrogen
c) 1 mole of ethanol [tex](C_2H_5OH)[/tex] contains = [tex]6.023\times 10^{23}atoms[/tex] of oxygen
Thus 0.989 moles ethanol [tex](C_2H_5OH)[/tex] contains = [tex]\frac{6.023\times 10^{23}}{1}\times 0.989=5.96\times 10^{23}atoms[/tex] of oxygen
Calculate the heat (in calories) released when 115 g of CHCl3 changes from a liquid to a solid at
its freezing point.
Answer: 8855 Joules energy is released when 115 g of [tex]CHCl_3[/tex] changes from a liquid to a solid at its freezing point.
Explanation:
Latent heat of freezing is the amount of heat released to convert 1 mole of liquid to solid at atmospheric pressure.
Amount of heat released to freeze 1 gram of [tex]CHCl_3[/tex] = 77 J/g
Mass of [tex]CHCl_3[/tex] given = 115 gram
Heat released when 1 g of [tex]CHCl_3[/tex] is freezed = 77 J
Thus Heat released when 115 g of [tex]CHCl_3[/tex] is freezed =[tex]\frac{77}{1}\times 115=8855J[/tex]
Thus 8855 Joules energy is released when 115 g of [tex]CHCl_3[/tex] changes from a liquid to a solid at its freezing point.
If some methane gas at 115 kPa and 33C is allowed to expand to 15.0dm^3 from 8.00 dm^3 when the temperature changed to 51.2 C. What pressure will the same amount of gas exert?
Answer:
228.4 kPa
Explanation:
From thw question,
PV/T = P'V'/T'..................... Equation 1
Where P = Inital pressure, T = Initial Temperature, V = Initial Volume, P' = fInal Pressure, V' = Final volume, T' = Final Temperature.
Make P' the subject of the equation
P' = PVT'/TV'...................... Equation 2
Given: P = 115 kPa, V = 15.0 dm³, T = 33°C = (33+273) K = 306 K, T' = 51.2°C = 51.2+273 = 324.2 K, V' = 8.00 dm³
Substitute these values into equation 2
P' = (115×15×324.2)/(306×8)
P' = 228.4 kPa.
4. Which of the following equations is
balanced?
A. Cl2 + NaBr-> Br2 + NaCl
B. 2Cl2 + NaBr-> 2Br2 + NaCl
C. Cl2 + NaBr --> Br2 + 2NaCl
D. 2Cl2 + 2NaBr--> Br2 + NaCl2
E. Cl2 + 2NaBr-> Br2 + 2NaCl.
Answer:
E. Cl2 + 2NaBr ----> Br2 + 2NaCl
Explanation:
Number of Cl molecules is 2 on the reactant and product side of the equation.
Number of Na molecules is 2 on the reactant and product side of the equation.
Number of Br molecules is 2 on the reactant and the product side of the equation.
As the reactant side is equal to the product side, the equation is balanced.
How many moles are in 297g of nh3?
Please show work, will give brainliest.
Answer:
17.5moles
Explanation:
The number of moles in a substance can be calculated by using the formula;
Number of moles (n) = mass (m) ÷ molar mass (MM)
According to this question, mass of ammonia (NH3) = 297g
Molar Mass of NH3 = 14 + 1(3)
= 17g/mol
n = 297/17
n = 17.47
Number of moles of NH3 = 17.5moles
Santee Cooper is stocking lakes Marion and Moultrie with 109,000 sterile grass carp. The grass carp, which eat hydrilla (Invasive species), are the most effective and least Intrusive means to control the weed. What type of control are they using?
A Invasive
B biological
C.chemical
D physical
Answer:
biological
Explanation:
i took the test and got it right
A Jeweler is making sapphire rings using 2 sapphires on every 1 ring. If the jeweler has 12 sapphires and 10 rings, what is the theoretical yield? (3 points)
O 5 sapphire rings
O 6 sapphire rings
O 10 sapphire rings
O 12 sapphire rings
3 (05 05 LC)
The theoretical yield is 6 sapphire rings.
What is Theoretical yield?This is the total product formed as a result of the complete conversion of
the reactants. In this scenario, the reactant is the 12 sapphires in which 2
of it is needed to produce one sapphire ring.
This however translates to the theoretical yield being 6 sapphire rings
which is gotten by:
2 sapphires = 1 ring
12 sapphires = x
Cross multiply
2x = 12
x= 12/2 = 6 sapphire rings.
Read more about Theoretical yield here https://brainly.com/question/25996347
spheres are not perfect in space. But <> is in the cause of their shape.
Answer:
<> yes
Explanation:
if a car collides with a barrier and hit with a hundred 50 Newtons of force how much force does the barrier put in the car?
Answer: 50 Newtons
Explanation:
Due to newtons third law of motion for every action there is an equal and opposite reaction or in this case the equal and opposite amount of force applied so the same 50 N is applied on the car by the barrier
did anyone do the phase change gizmo ever please give it to me i am not in the mood to try haha
Answer:
I'm going to give it a shot, but I'm not totally sure what you're talking about
Why are the offsprings of asexually reproducing organisms genetically identical to their offspring
Answer:
wdym?
Explanation:
hydrogen + copper(II) oxide= copper + steam, which substance is oxidized. explain your answers
A trait in which one allele for a gene contributes and the phenotype is an intermediate between the dominante
and recessive is what type of trait?
True or False. Chemical changes only rearrange the elements that are
already present.
True or False. The reactants and the products of a chemical equation
always have the same number of atoms.
Here's link to the answer:
tinyurl.com/wpazsebu
Which substances in the list can be used to write a complete combustion reaction? (4 points)
O 1, 2, and 3
O 2, 3, and 6
O 1, 4, and 5
O 1, 2, and 5
Answer:
B. 2, 3 and 6
Explanation:
The primary materials for a chemic combustion reaction are Fuel + O2 → CO2 + H2O!
Hope this could help! （*＾ワ＾*）
Answer:the answer is B
Explanation:
The ______ properties of a substance can be observed only when it undergoes a change to become an entirely different kind of substance with different properties.
Enter the answer
Answer:chemical
Explanation: