The answer is the half life of phosphorus-32 is of 14 days .
What is Half Life ?
The half-life of a radioactive isotope is the amount of time it takes for one-half of the radioactive isotope to decay.
The half-life of a specific radioactive isotope is constant; it is unaffected by conditions and is independent of the initial amount of that isotope.
Mass of atoms initially,
N₀ =2.0 g
Mass after 42 days,
N =0.25 g
mass left undecayed we have,
[tex]\rm\dfrac{N}{N_{0}} = \dfrac{1}{2^{n}}[/tex]
where n is number of half lives occured (the number of times it disintegrated into half of original)
[tex]\rm\dfrac{0.25}{2} = \dfrac{1}{2^{n}}[/tex]
[tex]\rm\dfrac{1}{8} = \dfrac{1}{2^{n}}[/tex]
[tex]\rm\dfrac{1}{2^{3}} = \dfrac{1}{2^{n}}[/tex]
n= 3
number of half lives occured in 42 days is 3
if half life is [tex]\rm t_{\frac{1}{2} }[/tex]
then
3* ( [tex]\rm t_{\frac{1}{2} }[/tex] ) = 42
[tex]\rm t_{\frac{1}{2} }[/tex] = 14 days
Therfore the half life of phosphorus-32 is of 14 days .
To know more about Half life
https://brainly.com/question/24710827
#SPJ1
16.
Which chemical reaction will always be spontaneous? (1 point)
an endothermic reaction in which
entropy increases
an exothermic reaction in which
entropy increases
an endothermic reaction in which
entropy decreases
an exothermic reaction in which
entropy decreases
Answer: an exothermic reaction in which entropy increases
Explanation:
Spontaneous reactions normally cause an increase in entropy and are also exothermic.
When FeCl2 reacts with K2S, potassium chloride and two compounds are produced. What is the name of the one of the compounds?
Because this is a double replacement reaction, the iron and potassium will swap places, giving [tex]\text{K}_{2}\text{Cl}_{2}[/tex] and [tex]\text{FeS}[/tex].
The names of these compounds are potassium chloride and Iron(II) sulfide
Calculate the number of hydrogen atoms in 58.1 grams butane.
This question involves the concepts of molar mass and molecular formula.
The number of hydrogen atoms in 58.1 grams butane are "10".
No. of Hydrogen AtomsThe molecular formula of butane is C₄H₁₀. And the molar mass of butane is 58.1 grams. Molar mass id the mass of the single molecule of a compound. Hence, it is very clear from the molecular formula and molar mass of butane that 58.1 grams of butane contains 10 atoms of hydrogen. Mathematically,
58.1 grams butane contains = 10 hydrogen atomsLearn more about molar mass here:
https://brainly.com/question/12127540
#SPJ1
what is the coordination number of an atom in FFC unit ?
[tex] \\ [/tex]
ty! :)
2.00L of gas is collected at 25.0 C and 745.0 mmHg What is the volume of this gas at STP?
Answer:
1.79
Explanation:
I showed maturity when I
I showed maturity when I turn 13 year old
You just finished your favorite soda which contained 39.0 grams of sugar (C12H22O11). How many molecules of sugar did you ingest?
The number of molecules of sugar, C₁₂H₂₂O₁₁ you ingest given the data is 6.86×10²² molecules
Avogadro's hypothesis1 mole of C₁₂H₂₂O₁₁ = 6.02×10²³ molecules
But
1 mole of C₁₂H₂₂O₁₁ = 342 g
Thus,
342 g of C₁₂H₂₂O₁₁ = 6.02×10²³ molecules
How to determine the molecules in 39 g of sugar342 g of C₁₂H₂₂O₁₁ = 6.02×10²³ molecules
Therefore,
39 g of C₁₂H₂₂O₁₁ = (39 × 6.02×10²³) / 342
39 g of C₁₂H₂₂O₁₁ = 6.86×10²² molecules
Thus, 6.86×10²² molecules are present in 39 g of sugar, C₁₂H₂₂O₁₁
Learn more about Avogadro's number:
https://brainly.com/question/26141731
#SPJ1
Oxidation state of Nitrogen in N2O5
Explanation:
Oxidation state of Nitrogen in N2O5 is +5
The specific heat of copper is 0.385 J/gºC. A 95.0 g block of
copper is heated to 77.9°C and placed into a calorimeter that
a
contains 42.0 mL of water at 20.4°C. Assuming no heat loss,
what will be the final temperature of the copper and water?
The final temperature of the copper and water in the calorimeter given the data is 30.3 °C
Data obtained from the questionSpecific heat capacity of copper (C꜀) = 0.385 J/gºCMass of copper (M꜀) = 95 gTemperature of copper (T꜀) = 77.9 °C Mass of water (Mᵥᵥ) = 42 mL = 1 × 42 = 42 gTemperature of water (Tᵥᵥ) = 20.4 °CSpecific heat capacity of the water (Cᵥᵥ) = 4.184 J/gºC Equilibrium temperature (Tₑ) =? How to determine the equilibrium temperatureHeat loss = Heat gain
MᵥᵥC(Tᵥᵥ – Tₑ) = M꜀C(Tₑ – M꜀)
95 × 0.385 (77.9 – Tₑ) = 42 × 4.184(Tₑ – 20.4)
36.575(77.9 – Tₑ) = 175.728(Tₑ – 20.4)
Clear bracket
2849.1925 – 36.575Tₑ = 175.728Tₑ – 3584.8512
Collect like terms
2849.1925 + 3584.8512 = 175.728Tₑ + 36.575Tₑ
6434.0437 = 212.303Tₑ
Divide both side by 212.303
Tₑ = 6434.0437 / 212.303
Tₑ = 30.3 °C
Learn more about heat transfer:
https://brainly.com/question/6363778
#SPJ1
NHCI(s) = NH3(g) + HCl(g) at 427°C, Kp = 4.8. Calculate Kc
[tex]\tt Kp=Kc(RT)^{\Delta n}[/tex]
NH₄Cl (s) ⇔ NH₃ (g) + HCl (g)
Δn = 2 (gas only)
R = 0.082
T = 427 + 273 = 700 K
4.8 = Kc (0.082 x 700)²
Kc = 1.45 x 10⁻³
Which sentence best describes the shapes of the moon over the course of about a month? (2 points)
Group of answer choices
Over the course of about a month, the shape of the moon does not change.
Over the course of about a month, the shape of the moon changes from a crescent, to a half circle, to three quarters of a circle, to a full circle.
Over the course of about a month, the shape of the moon changes from a crescent, to a full circle, to a half circle, and finally to three quarters of a circle.
Over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
The sentence best describes the shapes of the moon over the course of about a month is over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
What is full moon?The moon when looks like a full circle and having the highest brightness over its life cycle is called the full moon.
The full moon, crescent, half moon or no moon are all the stages of a Moon's lifecycle.
Over a period of 14 days, moon changes from a full moon to no moon. In the another 14 days, no moon changes to full moon. This cycle keeps on going for years and years.
Thus, the sentence best describes the shapes of the moon over the course of about a month is over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
Learn more about full moon.
https://brainly.com/question/22879736
#SPJ1
Answer:
Over the course of about a month, the shape of the moon changes from a full circle, to a crescent, and back to a full circle.
Explanation:
Calculate the number of moles in 5.2g CaCO3
Answer: 0.052moles
Explanation:
number of moles = given mass (g) / molar mass(g/mol)
n=m/M
n= 5.2g/ (40 + 12 + 48)g/mole
n=5.2g/100g/mol
n=0.052 moles
why we breath in oxygen but not nitrogen which is having big percentage
Answer:
Breathing an atmosphere of pure oxygen would damage the delicate tissues and blood vessels in our lungs, so it's a good thing that most of our atmosphere is nitrogen.Nitrogen is a fairly inert chemical (it does react, but not nearly as much as oxygen - this is why it is fairly stable in the atmosphere, whereas oxygen has to constantly be regenerated by photosynthesis).
Hope it Helps :))
Match the properties to the types of compounds they characterize.
Drag each label to the correct location on the table,
lonic Compounds
Metallic Compounds
Both
FREEBIE
The correct match of the compounds to their characters are:
Ionic compound: made of positive-negative ion and break into pieces easily.
Metallic compound: can be hammered into different shapes and conduct electricity.
Both: are held together with opposite ions, the high boiling point.
What are compounds?Compounds are made up by mixing two or more metals or non-metals.
Different compounds have different chemical properties.
Thus, the Ionic compound: is made of positive-negative ion and break into pieces easily.
Metallic compound: can be hammered into different shapes and conduct electricity.
Both: are held together with opposite ions, the high boiling point.
Learn more about compounds
https://brainly.com/question/13516179
#SPJ1
Hello!!
Who was Neil Bohr?
Explain the theory he introduced.
Answer:
In 1913, Niels Bohr proposed a theory for the hydrogen atom, based on quantum theory that some physical quantities only take discrete values. Electrons move around a nucleus, but only in prescribed orbits, and if electrons jump to a lower-energy orbit, the difference is sent out as radiation.
The equation shows the overall chemical reaction for photosynthesis, the process that plants use to make food from sunlight. Which statement explains why this is an endothermic reaction? 6CO2 + H2O + energy ---> C6H12O6 + 6O2
A) Water is one of the reactants.
B) A gas is released as one of the products.
C) The sugar dissolves in water.
D) Energy in the form of sunlight must be added.
During photosynthesis green plants use solar energy to produce fuel hence 'Energy in the form of sunlight must be added' that is option D is the correct option.
Why is photosynthesis an endothermic reaction?Photosynthesis is an endothermic reaction because green plants use solar energy in the form of sunlight, along with water and carbon dioxide in the air, to produce their food in the form of glucose.
Endothermic reactions are chemical reactions where the reactants utilize heat energy from the surroundings to form products.
Since energy as sunlight is used in the photosynthesis reaction, 'Energy in the form of sunlight must be added' that is option D is the correct option.
Refer the following link to know more about photosynthesis:
https://brainly.com/question/1388366
#SPJ1
Select the correct answer from each drop-down menu. A balloon holds a certain volume of air. In what three ways can the volume of the balloon be increased? the number of air molecules in the balloon the temperature of the balloon the pressure on the balloon
On increasing temperature , On decreasing pressure , on increasing the number of air molecules in the balloon volume will increase
What is Ideal Gas Law ?The ideal gas law (PV = nRT) relates the macroscopic properties of ideal gases.
An ideal gas is a gas in which the particles (a) do not attract or repel one another and (b) take up no space (have no volume).
Considering the gas inside the balloon to be ideal
We can understand from the ideal gas equation that
V∝ Temperature
V∝ Number of air molecules
V ∝ (1/P)
Therefore on increasing temperature volume will increase ,
On decreasing pressure volume will increase
and on increasing the number of air molecules in the balloon volume will increase.
To know more about Ideal Gas Equation
https://brainly.com/question/4147359
#SPJ1
In an electric toaster, electricity passes through thin metal wires (called filaments) inside the toaster, causing the wires to glow and heat up. The heat given off by the filaments then toasts the bread.
If 500 kilojoules of electricity are supplied to a toaster, which choice below could represent the total amount of heat energy given off by the filaments of the toaster?
A.
480 kilojoules
B.
520 kilojoules
C.
505 kilojoules
D.
630 kilojoules
Answer:
a. 480 kilojoules
Explanation:
good luck have a nice day
Convert 8.4 kg to grams
Answer:
8,400
Explanation:
multiply 8.4kg by 1000
Answer:
8400g
Explanation:
1kg=1000g
8.4*1000g=8400kg
I will mark brainliest
[tex]S_8 +120_2[/tex] → [tex]8SO_3[/tex] has been balanced correctly.
What is a balanced chemical equation?A balanced equation is an equation for a chemical reaction in which the number of atoms for each element in the reaction and the total charge is the same for both the reactants and the products.
[tex]S_8 +120_2[/tex] → [tex]8SO_3[/tex] has been balanced correctly and the rest are not balanced.
Learn more about balanced chemical equations here:
https://brainly.com/question/15052184
#SPJ1
A 0.600-L sample of a 3.75M solution of potassium iodide (KI) contains what mass of KI?
the molarity of a solution made by dissolving 5.67 g of potassium chloride in enough water to make 100.0 mL of solution.
Sodium hydroxide reacts with sulfuric acid according to the equation:
NaOH + H2SO4 + Na2SO4 + H2O
27. Name this type of reaction:
28. Balance the chemical equation:
Answer:
27) Double replacement
28) 2NaOH + H2SO4 --> Na2SO4 + 2H2O
What mass of Ca(OH)2 must be dissolved in 0.504 L of a solution to make a 0.56 M solution?
0.28 g
21 g
1.1 g
0.90 g
20.91200832 g of [tex]Ca(OH)_{2}[/tex] must be dissolved in 0.504 L of a solution to make a 0.56 M solution.
What is the molarity of a solution?
Molarity (M) is the amount of a substance in a certain volume of solution. Molarity is defined as the moles of a solute per litres of a solution. Molarity is also known as the molar concentration of a solution.
[tex]Molarity = \frac{Mole \;of \;solute}{Volume \;of \;solution \;in \;litre}[/tex]
Given data:
The volume of solution= 0.504 L
Molarity of [tex]Ca(OH)_{2}[/tex] = 0.56 M
Step 1: Calculating the mass of [tex]Ca(OH)_{2}[/tex]
Putting the given values in the equation.
[tex]Molarity = \frac{Mole \;of \;solute}{Volume \;of \;solution \;in \;litre}[/tex]
[tex]0.56 M = \frac{Mole \;of \;solute}{0.504 L }[/tex]
Moles of solute = 0.28224
[tex]Moles \;of \;solute= \frac{Given \;mass}{Molar \;mass}[/tex]
Molar mass of [tex]Ca(OH)_{2}[/tex] = 74.093 g/mol
Now, put the values in the formula.
[tex]Moles \;of \;solute= \frac{Given \;mass}{Molar \;mass}[/tex]
[tex]0.28224 mol= \frac{Given \;mass}{74.093 g/mol}[/tex]
Mass of [tex]Ca(OH)_{2}[/tex] =20.91200832 g
Hence, 20.91200832 g of [tex]Ca(OH)_{2}[/tex] must be dissolved in 0.504 L of a solution to make a 0.56 M solution.
Learn more about molarity here:
https://brainly.com/question/13152455
#SPJ1
Which of the following has more than one kind of monomer in its repeating unit? homodimer copolymer codimer homopolymer
Copolymer have more than one kind of monomer in its repeating unit.
What are Copolymers ?Those polymers that have more than one kind of monomer in its repeating unit are called Copolymers.
These are useful to modify the properties of polymers that needs more strength , durability etc.
It is a way of improving mechanical properties of a polymer .
A copolymer formed from two dissimilar molecules (as two olefins) is a codimer and the homopolymer and homodimer as the name suggest are made of one similar kind of monomers.
Copolymer have more than one kind of monomer in its repeating unit.
To know more about Copolymers
https://brainly.com/question/15736390
#SPJ1
What is small p value and large p value indicates for
Answer:
P value is commonly used. The prevalent use of P values to summarize the results of research articles could result from the increased quantity and complexity of data in recent scientific research.
Explanation:
Which soil particle is the smallest, drains water slowly, and holds too much water?
Answer:
Clay
Explanation:
Since Clay has a very small particle size it compacts or has a high surface area which slows the path of water, holding it for longer periods compared to other soil components.
Your vocal cords act like a guitar string. True or false and why
Answer:
True
Explanation:
Vocal folds vibrate when excited by aerodynamic phenomena; they are not plucked like a guitar string. Air pressure from the lungs controls the open phase. The passing air column creates a trailing “Bernoulli effect,” which controls the close phase.
Answer:
yes
Explanation:
well for some people because some times u can control your voice and sometimes u just get voice cracks
How much water must be added to 6.0 M silver nitrate in order to make 500 mL of 1.2 M solution?
The amount of water that must be added to 6.0 M silver nitrate to make 500mL of 1.2 M solution is : 2000 mL
Given data :
Concentration of siilver nitrate ( M₁ ) = 6.0 M
volume of solution ( V₁ ) = 500 mL
Conc of solution ( M₂ )= 1.2 M
Determine the amount of water that must be addedwe will apply the equation below
M₁V₁ = M₂V₂ ---- ( 1 )
where : V₂ = V₁ + water added ---- ( 2 )
V₂ ( Final volume ) = ( M₁V₁ ) / M₂
= ( 6 * 500 ) / 1.2
= 2500 mL
Back to eqaution ( 2 )
2500 mL = 500 mL + added water
therefore ; added water = 2500 - 500
= 2000 mL
Hence we can conclude that The amount of water that must be added to 6.0 M silver nitrate to make 500mL of 1.2 M solution is : 2000 mL.
Learn more about Volume : https://brainly.com/question/12410983
#SPJ1
Balance the following reaction:
K3PO4 (aq) +
_Ca(OH)2 (aq) →
_Ca3(PO4)2 (s) +
KOH (aq)
Answer:
3 Ca(OH)2 + 2 K3PO4 ---> Ca3(PO4)2 + 6 KOH
Explanation:
Just balance each atom on both sides.
crude oil is in soild form true or false
Answer:
false
Explanation:
it is a complex mix of hydrocarbons that caan only occur in liquid, gaseous, or solid form. Crude oil is often liquid form. But also includes gas and solid's known as which is found only in certain sands, so false is you're answer.
