Answer:
12 mmilligrams of Po-218 was the mass of the original starting material
Explanation:
The half-life of a radioactive material is the time taken for half the amount ofnthe original material present in a radioactive material to decay or disintegrate.
After each half-life, half the original material present at the start remains.
For the radioactive polonium-218 having a half-life of 3.04 minutes, it means that if 1 g is the starting material, after 3.04 minutes, 1/2 g will be remaining; after, 6.08 minutes 1/2 of 1/2 which is 1/4 of the starting material will be remaining; and after 9.12 minutes, 1/2 of 1/4 = 1/8 g will be remaining.
From the question, number of half-lives undergone after 9.12 minutes = 9.12/3.04 = 3 half-lives.
After 3 half-lives, 1/8 of the original material is remaining.
1/8 = 1.50 mg
The original mass of the sample at the start = 1.50 mg × 8 = 12 mg
Therefore, 12 milligrams of Po-218 was the mass of the original starting material.
Can I please get help with chemistry.
I got these three questions wrong and I’m wondering which answers would be right for the questions.
Answer: The 3rd one
Explanation: Electronegativity is a measure of how strongly atoms attract bonding electrons to themselves.
I might be wrong
which of the following would not form a covalent bond
Hydrogen and oxygen
Gallium and Iodine
Nitrogen and Oxygen
Carbon and Chlorine
Answer:
Gallium
Iodine
Chlorine
How many electrons did chlorine gain to become an atom with -1 charge ?
Answer:
17 electrons. On the right, the chloride ion has 18 electrons and has a 1− charge.
Explanation:
How much of a 0.74mg sample of uranium-235 will remain after 2.8x10^9
What is the molarity of a solution containing 9.0 moles of solute in 462 mL of solution
Answer:
[tex]\boxed {\boxed {\sf 19 \ M}}[/tex]
Explanation:
Molarity is a measure of concentration in moles per liter, so the formula is:
[tex]molarity= \frac{moles \ of \ solute}{liters \ of \ solution}}[/tex]
This solution has 9.0 moles of solute and 462 milliliters of solution. We must convert milliliters to liters. Remember that 1 liter contains 1000 milliliters.
Create a ratio.
[tex]\frac{ 1 \ L}{ 1000 \ mL}[/tex]Multiply by the value we are converting: 462 milliliters
[tex]462 \ mL *\frac{ 1 \ L}{ 1000 \ mL}[/tex][tex]462 *\frac{ 1 \ L}{ 1000}[/tex][tex]0.462 \ L[/tex]
Now we know both values and we can solve for the molarity.
moles of solute= 9.0 moles liters of solution = 0.462 L[tex]molarity= \frac{9.0 \ mol}{ 0.462 \ L}[/tex]
Divide.
[tex]molarity= 19.4805195 \ mol/L[/tex]
The original measurements of moles and milliliters have 2 and 3 significant figures respectively. We have to round our answer to the least number of sig figs, which is 2 in this case.
For the number we found, that is the ones place. The 4 in the tenths place (19.4805195) tells us to leave the 9 in the ones place.
[tex]molarity= 19 \ mol/L[/tex]
1 mole per liter is equal to 1 molar or M, so our answer is equal to 19 M.
[tex]molarity \approx 19 \ M[/tex]
The molarity of the solution is approximately 19 M.
Help help help I will give brainliest
Answer:
BUTANE
Explanation:
H3C--CH2--CH2--CH3
HERE, 4 CARBON AND SINGLE BOND SO, BUTANE
Answer:
D.BUTANE
Explanation:
THIS IS MY ANSWER OK
8.
(a) Tick (™) the box next to the correct statement about the mixture.
mixture of four elements
mixture of four compounds
mixture of two elements and two compounds
mixture of one element and three compounds
Answer:
mixture of four compounds
mixture of two elements and two compounds
Explanation:
it can be one of thosecan u tell me if its correct pls I'm studying this tooWhich of the following examples best represents heat?
1. A sample of platinum is 76°C.
2. A piece of plastic contains 57 J of energy.
3. A piece of wood burns at 350°C.
4. A toy car generates 45 J of kinetic energy.
Answer:
What I think it is it's.. 3?
what is chemical bonding?and types of chemical bonding there are?
Answer:
There are three primary types of bonding: ionic, covalent, and metallic. Ionic bonding. Definition: An ionic bond is formed when valence electrons are transferred from one atom to the other to complete the outer electron shell. Example: A typical ionically bonded material is NaCl (Salt).Explanation:
Hope it helps
#CarryOnLearning
An oxide of nitrogen contain its own volume of nitrogen
its vapour dentity is 22. Find the molecular formula
Of nitrogen Oxide
Answer:
NO2 is the molecular formula of nitrogen Oxide
Explanation:
Correct question
An oxide of nitrogen contain its own volume of nitrogen
its vapour dentity is 23. Find the molecular formula
Of nitrogen Oxide
Solution
As we know
Molecular Weight is equal to two times the vapour density
Hence, the molecular weight of Oxide of nitrogen is 2 * 22 = 44
Molecular weight of Oxide of nitrogen is the sum of atomic weight of nitrogen and oxygen
Molecular weight of Oxide of nitrogen = 14 + 16 *Y
14 + 16 *Y = 46
Y = 2
Hence, the formula is NO2
what are the possible values of ml for l=2
Answer:
-2, -1, 0, 1, 2
Explanation:
There are four types of quantum numbers;
1) Principal quantum number (n)
2) Azimuthal quantum number (l)
3) magnetic quantum number (ml)
4) Spin quantum number (s)
The azimuthal quantum number (l) describes the orbital angular momentum and shape of an orbital while the magnetic quantum number shows the projections of the orbital angular momentum along a specified axis. This implies that the magnetic quantum number shows the orientation of various orbitals along the Cartesian axes. The values of the magnetic quantum number ranges from -l to + l
For l= 2, the possible values of the magnetic quantum number are; -2, -1, 0, 1, 2
Which form of decay produces a nucleus similar to the element helium?
The answer Is Alpha particle
Explanation:
:D
The 500 cubic centimeter of 0.250 M Na2SO4 solution,
added to an aqueous solution of 15.00 grams of barium
chloride, resulted in the formation of a white precipitate of
barium sulfate. How many moles and how many grams of
barium sulfate are formed, respectively?
Answer:
0.072 moles, 16.776g.
Explanation:
The reaction of Na2SO4 and BaCl2 occurs as follows:
Na2SO4(aq) + BaCl2(aq) → BaSO4(s) + 2NaCl(aq)
To solve this question we must find the moles of each reactant. As the reaction is 1:1, the reactant with the low number of moles is limiting reactant. The moles of limiting reactant = Moles BaSO4. The mass can be obtained with the molar mass of BaSO4 -233.38g/mol-
Moles Na2SO4:
500cm³ = 0.500L * (0.250mol / L) = 0.125 moles
Moles BaCl2 -Molar mass: 208.23g/mol-
15.00g * (1mol / 208.23g) = 0.072 moles
The moles of BaSO4 are 0.072 moles and its mass is:
0.072 moles * (233.38g / mol) = 16.8g ≈ 16.776g
Scientific discoveries are often built on the previous findings of other scientists. Millikan’s oil drop experiment occurred after Thompson’s cathode ray tube experiment. What did both of these experiments collectively determine about the atom’s subatomic structure? Check all that apply.
Answer:
atoms contain negatively charged particles
the electron has a specific mass
Explanation:
got this shyt wrong for yall folks
Answer:
1 and 3
Explanation:
just had this question
you can test carbon dioxide gas with
Answer:
you can test carbon dioxide gas with calcium hydroxide
hope this is what you're looking for
stay safe and have a nice day
✌◕ ◡ ◕✌
7. Show the numerical setup of titration formula (MA)(VA)=(MB)(VB)
Answer:
i believe it is 17x=(4)x*4 +11*(0)
Explanation:
Help needed ASAP, I will mark your answer as brainliest.
Answer:
b
Explanation:
b
Mole ratios used for conversions come from?
Given: 2 AgNO3 + Cu -> Cu(NO3)2 + 2 Ag How many grams of AG can be produced if 200.0g of AgNO3 used?
Answer:
127 g of Ag are made in the reaction.
Explanation:
Reaction is: 2 AgNO₃ + Cu → Cu(NO₃)₂ + 2 Ag
If we only have data from nitrate, we assume the Cu is in excess.
We determine the moles of silver nitrate:
Mass / Molar mass → 200 g / 169.87 g/mol = 1.18 moles
Ratio is 2:2. If 2 moles of silver nitrate produce 2 moles of Ag, then
1.18 moles of salt, will produce 1.18 moles of silver
We convert mass to moles:
1.18 mol . 107.87 g/mol = 127 g
What is SnO2 compound name
You are given a clear-water solution containing potassium nitrate. How could you determine whether the solution is unsaturated, saturated, or supersaturated?
Answer:
If it is unsaturated, we can dissolve some more amounts of potassium nitrate into it Explanation:
What is the Molarity of a solution made by taking 2.5 moles and dissolving it into enough water to make 5.0 Liters of solution?
Answer:
.5 M
Explanation:
molarity = moles / liters
2.5/5 = .5 M
PLEASE PLEASE HELP CHEMISTRY
Sulfur (2.56 grams) was burned in a calorimeter with excess 02(g) . The temperature increased from 21.25C to 26.72C. The bomb had a heat capacity of 923 J/C, and the calorimeter contained 815 grams of water
Calculate the heat evolved as the sulfur burned:
Calculate the heat per mole of SO2 formed in the course of the reaction
S(s) + O2 (g) SO2 (g)
is there a way u could see if the element is acid,base or salt in the periodic table?
Answer:
OK i see
Explanation:
The raw materials used in making nylon?
[Please answer this]
Answer:
petroleum,natural gas,lime stone, coal,water,acetylene etc.
Answer:
petroleum,natural gas,lime stone,coal
water,acetylene
WILL GIVE BRAINLIEST
During an endothermic reaction, H for the reactants was −600 kJ/mol. Which of the following statements is correct about the H for the products the comparison of the energy in bonds? (5 points)
It is less than −600 kJ/mol, and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
It is less than −600 kJ/mol, and the amount of energy required to break bonds is less than the amount of energy released in forming bonds.
It is greater than −600 kJ/mol, and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
It is greater than −600 kJ/mol, and the amount of energy required to break bonds is less than the amount of energy released in forming bonds.
Answer:
It is greater than -600kJ/mol and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
Explanation:
In an endothermic reaction, the reaction requires a determined amount of energy to occurs.
The reaction of the problem has H = -600kJ/mol. The reaction is endothermic and the energy that the reaction needs is absorbed by the reactants. That means, the energy of products:
Is greater than -600kJ/mol and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
Answer:
It is greater than -600kJ/mol and the amount of energy required to break bonds is greater than the amount of energy released in forming bonds.
Explanation:
Pick the input(s) into the system. (select all that apply)
A battery powered robot with glowing eyes walking across the floor and making noise.
Radiant/Light Kinetic Energy
Nuclear Potential Energy
Chemical Potential Energy
None of these are inputs
Motion Kinetic Energy
Electrical Kinetic Energy
Answer:
So none of the option is correct.
Explanation:
The energy is the capacity of to work.
It is a scalar quantity.
According to the law of conservation of energy, the energy can neither be created and nor be destroyed, it can transform from one form to another.
For example, in case of a light bulb, the electric energy is converted into the light and heat energy.
When a battery operated robot with glowing eyes moving on the floor, the chemical energy of the battery is converted into the light energy and the kinetic energy so the law of conservation of energy holds good.
What is the pH of a solution with an [H+] of 9.34 x 10-6
Answer:
5.03Explanation:
The pH of a solution can be found by using the formula
[tex]pH = - log [ {H}^{+} ][/tex]
From the question we have
[tex]ph = - log(9.34 \times {10}^{ - 6} ) \\ = 5.0296...[/tex]
We have the final answer as
5.03Hope this helps you
Balance this equation
Fe2O2 + C -> Fe + CO2
2 FeO + 1 C ===》2 Fe + 1 CO2
Explanation:
Fe2O2+C-----> 2Fe+CO2
balanced equation..
hope it helps.
stay safe healthy and happy.......The solubility of a gas is 2.0 g/L at 50.0 kPa of pres-
sure. How much gas will dissolve in 1 L at a pressure
of 10.0 kPa?
our of
Answer:
That means, under 10.0kPa of pressure, 0.4g of gas can be dissolved in 1L
Explanation:
Based on Henry's law, the solubility of the gas is directly proportional to the pressure. The equation is:
P1S2 = P2S1
Where P is pressure and S solubility of 1, initial state and 2, final state of the gas.
Replacing:
P1 = 50.0kPa
S1 = 2.0g/L
P2 = 10.0kPa
S2 = ??
50.0kPa*S2 = 10.0kPa*2.0g/L
S2 = 0.4g/L
That means, under 10.0kPa of pressure, 0.4g of gas can be dissolved in 1L
Answer: 0.4 g/L
Explanation:
S2 = S1 x P2 / P1
S2= 2 g/L x 10 kPa / 50 kPa
CROSS OUT
S2= 2g/L x 10 / 50
S2= 20 g/L/50
S2= .4 g/L