Answer:
4.80×10³ years
Explanation:
Let the original amount (N₀) of ²²⁶Rn = 1 g
Therefore,
12.5% of the original amount = 12.5% × 1 = 12.5/100 × 1 = 0.125 g
Next, we shall determine the number of half-lives that has elapse. This can be obtained as follow:
Original amount (N₀) = 1
Amount remaining (N) = 0.125 g
Number of half-lives (n) =?
N = 1/2ⁿ × N₀
0.125 = 1/2ⁿ × 1
0.125 = 1/2ⁿ
Cross multiply
0.125 × 2ⁿ = 1
Divide both side by 0.125
2ⁿ = 1/0.125
2ⁿ = 8
Express 8 in index form with 2 as the base
2ⁿ = 2³
n = 3
Thus, 3 half-lives has elapsed.
Finally, we shall determine the time taken for only 12.5% of the original sample of ²²⁶Rn to remain.
This can be obtained as follow:
Half-life (t½) = 1.60×10³ years
Number of half-lives (n) = 3
Time (t) =?
t = n × t½
t = 3 × 1.60×10³
t = 4.80×10³ years.
Thus, it will take 4.80×10³ years for 12.5% of the original sample of ²²⁶Rn to remain.
Plssss help ASAP I really need help with this y’all I’m bad at science
Is the Swedish timber industry more likely a result of good resource availability or a lack of trees elsewhere on Earth?
Answer:
The forest products industry plays a major role in the Swedish economy, and accounts for between nine and 12 percent of Swedish industry's total employment, exports, sales and added value. It includes companies within the pulp and paper industry, as well as the wood-mechanical industry.
How many electrons and protons does the sodium ion have 11 protons and 11 electrons
Answer:
A sodium ion Na+ contains 10 electrons, 11 protons, and 12 neutrons.
Explanation:
The mass of a salt in grams that will dissolve in 100 mL of water.
____________ A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
_________ The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
__________ A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
__________ The maximum number of moles of a salt that will dissolve in 1 L of solution.
a. A decrease in the solubility of an ionic compound as a result of the addition of a common ion.
b. The mass of a salt in grams that will dissolve in 100 mL of water.
c. A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved.
d. The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation.
e. The maximum number of moles of a salt that will dissolve in 1 L of solution.
Answer:
Solubility : The mass of a salt in grams that will dissolve in 100 mL of water
Saturated solution : A solution that has dissolved the maximum amount of a compound at a given temperature. Any further addition of salt will remain undissolved
Solubility product constant :The product of the molarities of the dissolved ions, raised to a power equal to the ion's coefficient in the balanced chemical equation
Common ion effect : A decrease in the solubility of an ionic compound as a result of the addition of a common ion
Molar solubility : The maximum number of moles of a salt that will dissolve in 1 L of solution
Explanation:
Solubility is expressed usually as the mass of solute per 100 grams or 100 ml of solvent.
Molar solubility of a solid is expressed as the concentration of the dissolved solid in a saturated solution.
Solubility product constant is defined as the equilibrium constant in which a solid ionic compound is dissolved to produce its ions in solution. It is represented as
The common-ion effect is the decrease in solubility of a sparingly soluble salt by the addition to the solution of a soluble compound with an ion in common with the precipitate.
Saturated solution is defined as the solution in which no more solute particles can be dissolved in the solvent.
Rank the following compounds in order of increasing solubility in water. Items (4 items) (Drag and drop into the appropriate area) No more items Items in order most soluble CaO BaO KCI KI
I have tried CaO> BaO > KCl > KI, this is incorrect.
Answer:
CaO < BaO < KCl <KI
Explanation:
Let us remember that the solubility of an ionic substance in water depends on the magnitude of the lattice energy and the hydration energy. If the hydration energy is equal to or is greater than the lattice energy, the substance dissolves in water.
However, the lattice energy depends on the size of the ions. The smaller the ions in the ionic compound, the higher the lattice energy and the lesser the solubility of the ionic compound.
KI has the least lattice energy and the highest solubility in water while CaO has the highest lattice energy and the least solubility in water.
The force of gravity can act between two people.
True or false??
I don’t understand please help
what is a mole and its properties
One mole of a substance is equal to 6.022 × 10²³ units of that substance (such as atoms, molecules, or ions). The number 6.022 × 10²³ is known as Avogadro's number or Avogadro's constant. The concept of the mole can be used to convert between mass and number of particles.
Solution Mass of NaCl (9) Volume of water (mL)
A
5.0
50.0
B
5.0
75.0
с
5.0
100.0
D
5.0
125.0
Which of the solutions has the highest salt concentration?
O A Solution B
B. Solution A
O
C. Solution C
D. Solution D
Divide the volume of water with mass of salt and multiply with 100 you'll get the concentration percentage
answer is B, because solution A's percentage is 10%
brainliest plz
What is h+ concentration associated with a pH=10.2
A. 10.9
B. 6.3*10^-11
C. 3.1
D. 3.2 * 10^-3
Answer:
6.3*10^-11
no reasoning i just know thats the answer you dont have to trust me.
How many moles of LiOH are in a 4.5 M solution containing 1.5 L of water?
Answer:
d
Explanation:
If 22.4L = I moles How many liter of CO2 are produced if you produce 9.6 moles of CO2?
Answer:
215 moles
Explanation:
[tex]9.6mol CO_{2} (\frac{22.4 L CO_{2}}{1 mol CO_{2}} ) = 215 L CO_{2}[/tex]
5.07 x 10^24 atoms of antimony is how many moles?
8.98 mol
7.99 mol
4.82 mol
8.42 mol
Answer:
8.42 moles (3 sig. figs.)
Explanation:
Given 5.07 x 10²⁴ atoms of antimony (Sb) => ? moles Sb
1 mole of any substance contains 6.02 x 10²³ particles ( atoms or molecules)
∴ Think in terms of 'how many 6.02 x 10²³'s are in 5.07 x 10²⁴ atoms Sb?
That is => moles Sb = 5.07 x 10²⁴ atoms Sb / 6.02 x 10²³ atoms Sb/mole Sb
= 8.42192691 moles Sb (calculator answer) ≅ 8.42 moles (3 sig. figs.)
match the following
Answer:
Ai --> Bii
Aii --> Bi
Aiii --> Bv
Aiv --> Biii
Av --> Biv
Explanation:
For Ai, naphthalene sublimes directly from a solid to gas when heated at around 80 degree Celsius.
For Aii, Ozone has a molecular formula of O₃.
For Aiii, weeds are normally considered as "unwanted" plants. Many people may consider using herbicides to clear the weeds in their gardens.
For Aiv, filtration is a physical method for separating solid and liquid from a mixture. A filter paper is normally used, in which the complex structure of the paper only allows fluid to pass through it, but not the solid ones. The solid left behind on the filter paper is called "residue".
For Av, photosynthesis is a chemical reaction that occurs in the leaves of a plant, which produces food for plants to survive. Carbon dioxide, water and light are required for photosynthesis to take place.
Identify the techniques used in the work-up and characterization of benzoic acid. The analytical method used to confirm the structure and functional groups of the product NMR spectroscopy The technique used to separate the pure product from any excess reagent, impurities, and byproducts Recrystallization The quick, numeric analysis used to characterize the product and assess the purity Melting point.
Answer:
Explanation:
[tex]\text{From the list of the options given; we are to identify the suitable techniques} \\ \\ \text{for the characterization of benzoic acid.}[/tex]
[tex]\text{The analytical method used to confirm the structure and functional groups}\\ \\ \text{present in the product is} \ \ \mathbf{IR \ spectroscopy.}[/tex]
[tex]\text{The technique used to separate pure products from any excess reagents,} \\ \\ \text{impurities, and byproducts is}\ \ \mathbf{Recrystallization.}[/tex]
[tex]\text{The quick, numeric analysis done to characterize the product and assess the purity is}[/tex][tex]\mathbf{melting \ point.}[/tex]
the form of EMR that has less energy per photon than microwaves is ____?
Answer: radio wave frequencies have longer wavelengths and smaller
Energies per photon
Which of the following wavelengths has the lowest frequency?
10mm
10nm
10km
10cm
10m
Answer:
10m es su respuesta
Explanation:
espero te sirva
What is the percent composition of hydrogen in glucose
Answer:
67%Explanation:
Thus the % composition of glucose by mass is carbon 40.0 % oxygen 53.3 % hydrogen 6.7 % in this way, the % composition by mass of any compound can be calculated provided that is formed is known.A chemistry student is given 4.00 L of a clear aqueous solution at 22°C. He is told an unknown amount of a certain compound X is dissolved in the solution. The student allows the solution to cool to 22 C. The solution remains clear. He then evaporates all of the water under vacuum. A precipitate remains. The student washes, dries and weighs the precipitate. It weighs 0.56 kg.
Required:
Using only the information above, Calculate the solubility of X in water at 22° C. If you said yes, calculate it Be sure your answer has a unit symbol and 2 no .0 it. significant digits.
Answer:
The responses to the given points can be defined as follows:
Explanation:
In point 1:
The answer is "No".
In point 2:
The mass of solute = The mass of precipitate [tex]= 0.56\ kg =0.56\ \times 1000 = 560 \ g[/tex]
Calculating the solubility:
[tex]= \frac{\text{mass of solute in g}}{\text{volume of solution in ml}}\\\\ = \frac{560}{ 4000} \\\\ = 0.14 \ \frac{g}{ml}[/tex]
You have 281 kilojoules how many kilocalories is it need to know ASAP
Consider the fatty acid. A carboxylate salt is attached to a 19 carbon chain, where double bonds are present between carbons 5 and 6, between carbons 8 and 9, between carbons 11 and 12, and between 14 and 15. The carboxylate carbon is carbon 1. All double bonds are cis. Which of the designations are accurate for the fatty acid
Answer:
ω-3 fatty acid and 19:4(Δ5,8,11,14)
Explanation:
From the image attached below:
We can see the structure of the delta nomenclature showing the numbers of carbons, numbers of double bonds, and the locations of the double bonds in the structure of the carboxylate salt.
Also, we can see the structure of the fatty acid where; the location of the first double bond from the methyl end is shown.
Hence, the designation which are accurate for these structures are:
ω-3 fatty acid and 19:4(Δ5,8,11,14)
A separatory funnel contains the two immiscible liquids water and toluene. Use the given densities to determine which layer is on top and which is on the bottom in the binary mixture.
Solvent Density (g/mL)
toluene 0.87
water 0.998
Drag and drop each label into the box to indicate the position of the liquid in the mixture.
Top layer
Bottom layer
Answer:
Top layer TolueneBottom layer WaterExplanation:
When two non-miscible liquids are put together, the one with the higher density will be on the bottom, while the one with the lower density will be on top.
Meaning that in this problem's case toluene would be on the top layer and water in the bottom layer.
Of the three Intermolecular forces, the type with the largest dissociation energy is ________.
A. Dipole-dipole interactions
B. Dispersion forces
C. Hydrogen bonds
Answer:
C. Hydrogen bonds
Explanation:
Strongest intermolecular force
Hydrogen Bonding (H-Bonding)
Hydrogen bonds are caused by highly electronegative atoms. They only occur between hydrogen and oxygen, fluorine or nitrogen, and are the strongest intermolecular force.
Answer: C hydrogen bonds
Explanation:
What is the formula for Dicarbon trioxide
Answer:
diboron trioxide Formula: B 2 O 3 Molecular weight: 69.620 CAS Registry Number: 1303-86-2
Explanation:
hope that helps you╰(*°▽°*)╯what is the molecular formula of a compound with the empirical SO and molecular weight 96.13?
Answer:
Explanation: A compound with the empirical formula SO has a molecular weight of 96.13
Which of the following is the best hypothesis?
A. If paper is burned, the products will be carbon dioxide and water.
B. At what temperature does a piece of notebook paper start to burn?
C. Some people use burning paper to help get a campfire started.
D. You should recycle paper instead of burning it.
Answer:
THE CORRECT ANSWER IS A
sorry for caps
Match the function to the part of the cell.
1.lysosome
A.serves as a temporary storage area for nutrients and waste materials
2.vacuole
B.breaks down waste materials
3.chloroplast
C.converts energy from the sun to food energy
Answer: Chloroplast: Converts energy from the sun to food energy
Answer: Vacuole: Servers as a temporary storage area for nutrients and waster materials.
Answer: Lysosome: Breaks down waste materials
Explanation: Dude above me is wrong
What is the molality of a 10.0 % by mass solution of NaCl?
(molar mass of NaCl = 58.44 g/mol)
mol/kg
On CK-12 all of these answers are correct
1.9
1.888
1.89
1.88
The molality of a 10.0 % by mass solution of sodium chloride (NaCl) is 1.7M.
How do we calculate molarity?Molarity of any solution will be calculated as number of moles of solutes present in per litre of the solution.
Moles of the substance will be calculated as:
n = W/M, where
W = given mass
M = molar mass
Given that percent mass of NaCl = 10% i.e. 10g of NaCl is present in 100 g of solution.
We know that 1 g = 0.001 L
100 g = 0.1 L
Moles of NaCl = 10g / 58.44g/mol = 0.17 mol
Molarity of NaCl = 0.17 / 0.1 = 1.7M
Hence required molarity is 1.7 M.
To know more about molarity, visit the below link:
https://brainly.com/question/489225
What is thePercent composition of dichlorine heptoxide?
Answer:
The percent composition of dichlorine heptoxide is 38.76% CI and 61.24% O
Answer:
38.76%cl and 61.24%o
Explanation:
the percent composition of dichlorine heptoxide is 38.76%Cl and 61.24%O
How many fluorine atoms are there in 39.4 moles of CF4?
Answer:
here
Explanation:
Answer: 4
A molecule of carbon tetrafluoride, CF4 , is made up of 1 carbon atom bonded to 4 fluorine atoms. Each carbon atom weighs 12.0 amu and each fluorine atom weighs 19.0 amu so 1 CF4 molecule weighs 1×12.0 amu + 4×19.0 amu = 88.0 amu. This number, 88.0, is called the molecular weight (or molecular mass) of CF4.