Based on the half-lives of the given materials:
Number of years it take for 93.75% of a sample of radium-226 to decayis 6400 years.Fraction of Sodium-24 remaining after 105 days is 0.78 % .What is the half-life of a substance?The half-life of a substance is the time taken for half the amount present in the original sample of a substance to decay.
The half-life of a substance is constant.
Considering the given questions:
1. the half life of radium-226 is 1,600 years, how long will it take for 93.75% of a sample of radium-226 to decay?
The amount of remaining after 93.75% have decayed = 100 - 93.75 = 6.25%
The number of half-lives that will result in 6.25 % remaining will be:
After first half life = 50% remains
After second half life = 25% remains
After third half life = 12.5% remains
After fourth half life = 6.25% remains
Number of years taken = 4 * 1600
Number of years taken = 6400 years
2. Sodium-24 has a half life of 15 days. What fraction of the original amount of sodium-24 will remain in a sample after 105 days?
Number of half lives after 105 days = 105/15
Number of half lives after 105 days = 7 half lives
Fraction remaining = (¹/₂)⁷
Fraction remaining = 0.78 %
Learn more about half-lives at: https://brainly.com/question/2320811
#SPJ1
An atom of Calcium has 20 protons and 20 electrons. The atom loses 2 electrons.
What will be the charge on the ion that forms?
A +2
B -2
C +18
D -18
Based on the given question about an atom of Calcium and losing electrons, the charge on the ion that forms would be 18.
What is a Proton?This refers to the subatomic particle that is positively charged and can be found in the nucleus of every atom.
Calculations and Parameters
Given that:
Ca^2+ represents an ion with 20 protons and 18 electrons.
A calcium atom has 20 protons and 20 electrons.
The 2+ charge close to the symbol shows a loss of two electrons: 20-2=18.
With this in mind, the charge on the ion that forms would be 18.
Read more about protons and electrons here:
https://brainly.com/question/6258301
#SPJ1
Detective Sanders asked his colleague to take a look at the ridge characteristics he has found. What is he MOST likely observing?
A.
tire tracks
B.
glass fractures
C.
soil samples
D.
fingerprints
Consider the following ionic
compounds and determine which
has the higher melting point.
A. BeCl₂
B.Al₂S3
Answer:
Al2S3
Explanation:
Both are ionic, so to find out which one has the higher melting point, remember that opposite forces attract, and the stronger the opposite forces are, the stronger they attract.
BeCl2 is made of Be 2+ and Cl (1)-, while Al2S3 is made of Al 3+ and S2-
Since 3 and 2 multiply to a larger number than 2 and 1, the attractive forces between a 3+ ion and a 2- ion are stronger than that of a 2+ ion and a 1- ion. The stronger the forces between atoms, the higher the melting point is.
What would the empirical formula be for a compound that had 37.47% Carbon, 12.61% Hydrogen and 49.92% Oxygen be? Only write WHOLE NUMBERS!
Answer: CH40 ( the 4 is not a whole number )
Explanation: If we assume that we have a sample of 100g of the compound, then that would mean we have 37.47 grams (3.12 moles) of carbon, 12.61 grams (12.48 moles) of hydrogen, and 49.92 grams (3.12 moles) of oxygen. The molar ratio of C:H:O is 3:12:3, reducing to 1:4:1, giving the empirical formula of CH4O.
rubidium has two common isotopes rubidium has two common isotopes, rubidium-85 and rubidium-87 atoms of rubidium-87, what is the atomic mass of rubidium
The atomic mass of rubidium is 86.09 amu as rubidium has two common isotopes, rubidium-85 and rubidium-87 is 84.42 amu.
Abundance of Rubidium-85 = 72.1%
Abundance of Rubidium-87 = 26.7%
To calculate average atomic mass of rubidium -
The percentage of abundances are divided by hundred to obtain a decimal value.
The obtained value of each isotope is multiplied by its atomic mass.
All the isotopic values are added.
So,
Rb-85 = 72.1 = 0.721
100
Rb-87 = 26.7 = 0.267
100
Atomic mass of Rb-85 = 0.721 × 84.91
= 61.22 amu
Atomic mass of Rb-87 = 0.267 × 86.91
= 23.20 amu
Hence,
the average atomic mass = 61.22 amu + 23.20 amu
= 84.42 amu
Therefore, atomic mass of rubidium is 84.42 amu.
To learn more about rubidium,
brainly.com/question/28657648
#SPJ1
Based on what you know about atomic structure, what can you infer about the word "nuclear?"
Answer:
nuclear is the center part of an atom
Explanation:
it contains neutron and proton (positive charged)
it gets revolved by electron
A quantity of 7.181 g of an organic compound is dissolved in water to make 288.0 mL of solution. The
solution has an osmotic pressure of 1.43 atm at 27°C. The analysis of this compound shows that it
contains 41.8 percent C, 4.7 percent H, 37.3 percent O, and 16.3 percent N. Calculate the molecular
formula of the compound.
Answer:
Explanation:
was up yo boi
If instead of using the blue dye, we had used a red dye, what changes would you make in your experimental procedure to determine the rate law for the oxidation of the red dye by sodium hypochlorite?
The changes that I would make in my experimental procedure to determine the rate law for the oxidation of the red dye by sodium hypochlorite is that the wavelength at which the dye concentration is calculated would be changed as a result of the operation.
What is the experiment procedure about?Since there would be an alteration in the wavelength at which the dye concentration, You shouldn't measure at the wavelength where the blue dye absorbs since you would no longer be attempting to detect the rate of oxidation of the blue dye.
Most likely, the red dye absorbs more light at a different, lower wavelength. Decide on the best wavelength to use to measure the red dye concentration, then switch to that wavelength to evaluate the kinetics.
Learn more about experimental procedure from
https://brainly.com/question/26126956
#SPJ1
Choose the best answer.
Perform the indicated calculation. You may use a calculator. Remember to round your
answers according to the rules for significant figures.
0.0204 g
+ 0.002 g
Answer:
0.022
Explanation:
The first number is:
0.0204, and has 4 sig figs (bolded numbers are sig fig contributors)
The second number is:
0.002 and has 3 sig figs
The answer we get must have the same number of sig gifs as the lowest sig fig count of the given values. In this case, the answer would have 3 sig figs and not 4 because the smaller one is 3.
Do the calculations and then round.
0.0204 + 0.002 = 0.0224, and since we only want 3 sig figs, go from the right of the period and count 3 numbers, which would be 0.0224, and notice how the 4 isn't included. This means that the final answer should be 0.022
Which of the following reactions would produce a white precipitate?
(1) Heating sodium chloride strongly
(2) Mixing aqueous solution of silver nitrate with sea water
(3) Adding quicklime to dilute hydrochloric acid
A(1) only
B(2) only
C(1) and (3) only
D(2) and (3) only
Answer:
Aniline reacts with bromine water to give a white precipitate.
net ionic equation for the precipitation of calcium phosphate from aqueous solution
The net ionic equation for the precipitation of calcium phosphate from aqueous solution is Ca²+ (aq)+ S²- (aq)=>CaS(s)-----> CaS(s).
How is a precipitation process expressed in a net ionic equation?For a precipitation reaction, the net ionic equation is written by first knowing the precipitate, then use the solubility rules (if there are any).
Then one can write down the precipitate's formula that was made to the right of an arrow. The ions that react to get the precipitate as the reactants to the left of the arrow should have their formulas written down also:
Hence:
Since the molecular fomular is: H2S(aq) + CaCl2(aq) -------> CaS(s) + 2HCl(aq)
Then the full ionic equation will be: 2H^+(aq) + S²-(aq) + Ca²+(aq) + 2Cl^-(aq) -------> CaS(s) + 2H^+(aq) + 2Cl^-(aq)
Learn more about precipitation from
https://brainly.com/question/21319390
#SPJ1
Predict the chemical formula for the ionic compound formed by Hg₂²⁺ and CO₃²⁻
The chemical formula for the ionic compound formed by Hg₂²⁺ and CO₃²⁻ is Hg₂²⁺ + CO₃²⁻ ⇄ HgCO₃
What is chemical formula?
A chemical formula can be defined as the expression that states the number and type of atoms present in a molecule of a substance.
When a cation and anion combine to form a compound, there will be transfer of electron form one ion to another creating ionic bond in molecule formed.
The chemical formula for the ionic compound formed by Hg₂²⁺ and CO₃²⁻ is determined as follows;
Hg₂²⁺ + CO₃²⁻ ⇄ HgCO₃
Thus, the chemical formula for the ionic formed by the ions will have have electron transfer from one ion to another.
Learn more about ionic compound here: https://brainly.com/question/2687188
#SPJ1
which diagram below accurately identifies displacement and additive plating? be sure to read the description for each and look at the labels under each diagram
The second image that is shown below accurately identifies displacement and additive plating.
What is plating?The term plating is actually an electrochemical process. This implies that it has to do with a chemical reaction that involves electrochemistry. The term plating has to do with the situation where a metal is wholly or partially covered by another metal in a electrochemical process. Recall that electrons must be transferred as part of the process as it is an electrochemical process.
In the process of an additive plating, has to do with a situation where a metal is merely added to the surface of another metal without replacing the metal. In fact, the surface does have the two metals.
In the case of the displacement plating, the metal that was initially on the surface is replaced and then we have a whole new metal that is present on the surface as shown in the image in the question.
Learn more about plating:https://brainly.com/question/20078989
#SPJ1
help me please if you can
Solutions:
• Hot air rises because as the air is heated, it enlarges or swell up, resulting in reduced density, hence it rises .
,• The molecules in the hot air also heats up and move faster and spreads out and hits the inside of the baloon pushing it upwards since the its density is lesser than when it was cooled.
3. Pluto picks up a snow globe and shakes it, he notices that the "snow" settles at the bottom after a few
seconds.
The snow globe can be classified as a:
a. suspension
b. element
c. compound
d. homogeneous mixture
A snow globe is a suspension combination because it shakes up with snow all over it, which eventually settles.
What is the crystal-clear substance in snow globes?Glycerin, a transparent liquid that is often manufactured from vegetable oils, is one of the secrets to making a snow globe. It is used frequently to reduce the impact of glitter and agitated water on the appearance of snowfall. Your snow globes risk drying out, cracking, and color fading if the right precautions aren't taken to protect them. In general, you should store your snow globes away from hot surroundings, bright sunlight, and other risky places where they could break.
To know more about suspension :
https://brainly.com/question/17650174
#SPJ9
_______data are information
that can be grouped into categories.
Answer: Categorical data
Explanation: As the name implies, are usually grouped into a category or multiple categories. Similarly, numerical data, as the name implies, deals with number variables.
Hope this helps!!! :)
[E2E] question 1646287324361
I'm not able to help you with your question
ω
[tex]\text{y = ax + b}[/tex]
How many grams of nitrogen are in 13.2 grams of N₂O₂?
The mass of the nitrogen in solution of N₂O₂, n = 4.55 g.
Equation :To calculate the mass of nitrogen using formula,
n = W / w
where,
n is mass of nitrogen
W is molecular weight of N₂O₂
w is weight of solution
So, given data are :
w = 13.2 g
W = 60.013 g
n = ?
Now, putting the values we get,
n = 60.013 / 13.2
n = 4.55 g
Hence, the mass of the nitrogen in solution of N₂O₂, n = 4.55 g.
Dinitrogen dioxide :The inorganic substance dinitrogen dioxide has the chemical formula N₂O₂. It is conceivable to have many structural isomers. Based on ab initio calculations, the covalent bonding pattern O=N-N=O is projected to be the most stable isomer and is the only one that has been created experimentally.
To know more about solution :
https://brainly.com/question/7932885
#SPJ9
A chemist measures the amount of oxygen gas produced during an experiment. He finds that 2.1 g of oxygen gas is produced. Calculate the number of moles of
oxygen gas produced.
Round your answer to 2 significant digits.
The number of moles of oxygen produced is 0.065 mol.
What is meant by moles?The molarity of a chemical compound is largely decided in chemistry by trying to divide the mass of a sample of that compound by the amount of substance of that compound, which corresponds to the number of moles in that specimen, evaluated in moles. A substance's molar mass is a bulk property rather than a molecular one. A substance's molar mass is its mass in grams per mole of the compound. A mole is the measurement of the quantity of atoms, molecules, or ions in a substance. A mole is 6.022 1023 molecules of any given substance.
The total mass of all the atoms in a molecule expressed in grams per mole is known as the molar mass.
The mass of the oxygen gas produced = 2.1 g
The molar mass of oxygen gas , [tex]O_{2}[/tex] = 2 × 16 g/mol
= 32 g/mol
The formula for the calculation of moles
= mass taken / molar mass
Thus,
Moles = 2.1 / 32
= 0.065 mol
To know more about molar mass , visit:
https://brainly.com/question/20552052
#SPJ9
The particle that determines the mass of the atom, along with the proton, is the
ion
electron
nucleus
neutron
proton
its neutron
Explanation:
Neutrons are located in the nucleus with the protons. Along with protons, they make up almost all of the mass of the atom. The number of neutrons is called the neutron number and can be found by subtracting the proton number from the atomic mass number.
The liquid filtrate that you collect after filtering your solid product will be acidic.
The liquid filtrate that you collect after filtering your solid product will be acidic no its not acidic its basic
Filtration is a technique used either to remove solid impurities from an organic solution or to isolate an organic solid and the two types of filtration commonly used in organic chemistry laboratories are gravity filtration and vacuum or suction filtration
Filtration is the process in which solid particles in a liquid or gaseous fluid are removed by the use of a filter medium that permits the fluid to pass through but retains the solid particles and either the clarified fluid or the solid particles removed from the fluid may be the desired product and when we filtrate the liquid part then precipitation is stick means solid part is stick to the filter paper and other liquid part is filtered and this ppt is not the acidic its a basic part
Know more about filtrate
https://brainly.com/question/18152841
#SPJ1
HELP ME CHEMISTRY QUESTION PURE SUBSTANCE OR MIXTURE 100 POINTS
Answer: Bro you can use Bartleby for this answer
Explanation:
Find the average atomic mass of a sample that has 75%
Element-133, 20% Element-132 and 5% Element-134.
Answer:
Average atomic mass: 132.85a. m. u.
Explanation:
The average atomic mass could be found by:
Average mass = ∑ (Abundance percentage × isotope mass)
⇒ Average mass = (0.75 × 133) + (0.20 × 132) + (0.05 × 134) = 132.85a. m. u.
Hope this helps! :)
Given the chemical equation: SiO2 (s) + 4KF(g) --> SiF4(g)+ 2H2O(l) Delta H= -184kJ
How much heat is released in the formation of 75.0 g of water?
The heat is released in the formation of 75.0 g of water is 14.78 kJ.
What is chemical equation?Chemical equation is defined as a chemical reactions are represented symbolically in which the reactants and products are expressed in terms of their respective chemical formulae.
There are basically five types of chemical equation.
Combination reactionDecomposition reactionReplacement reactionDouble replacement reactionCombustion reactionSiO2 (s) + 4KF(g) --> SiF4(g)+ 2H2O(l)
According to the reaction
ΔH = -184 / 2 moles of water
N(water) = Q / ΔH
N(water) = 75 / - 184 / 2 moles of water
N(water) = 0.82 mole
M(water) = 18.02 g/mole
M(water) = N(water) = 0.82 x 18.02 g/mole
= 14.78 kJ
Thus, the heat is released in the formation of 75.0 g of water is 14.78 kJ.
To learn more about chemical equation, refer to the link below:
https://brainly.com/question/28294176
#SPJ1
An alloy is made of different elements bonded together. Why is an alloy not considered a compound?
Select all the correct answers.
- Atoms in an alloy share electrons, but atoms in compounds do not.
- The properties of an alloy are similar to the properties of its components.
- The elements in an alloy are not combined in fixed proportions.
- Alloys are made up of ions, which do not form compounds.
The properties of an alloy are similar to the properties of its components. The elements in an alloy are not combined in fixed proportions is an alloy not considered a compound
What distinguishes an alloy from a compound?Although the physical characteristics of the alloy are intermediate to those of its component metals, the chemical characteristics of each element are unaltered. Physical methods can be used to separate an alloy (separated by melting). A compound is a collection of several components that are connected by chemical connections.
Metal mixes or blends of a metal and another element are known as alloys. A combination of metallic phases or a solid solution of metal elements, known as an alloy, are both possible (a heterogeneous mixture of two or more solutions).
An alloy is a combined, homogenous combination of a metal with other metals or non-metals.
learn more about alloy refer
https://brainly.com/question/16935193
#SPJ9
Answer: Answer is B and C
b: the properties of an alloy are similar to the properties of its components.
c: The elements in an alloy are not combined in fixed propo
Explanation:
If equal masses of the following compounds were dissolved in water to prepare 100.0
mL of solutions which of them would have the lowest concentration of sodium ions?
O Na₂SO4 (molar mass= 142.04 g/mol)
O Na3PO4 (molar mass = 163.94 g/mol)
O NACIO4 (molar mass = 122.44 g/mol)
ONaNO3 (molar mass= 84.99 g/mol)
O Na₂CO3 (molar mass= 105.99 g/mol)
Answer:
Explanation:
yt maybe
consider an excited-state hydrogen atom. What is the energy of the electron in the n = 4 level?
The energy of the electron is obtained as -0.85 eV.
What is the Bohr model?From the Bohr model of the atom, we know that the electrons that can be found in the shells of hydrogen do have a specific energy level where they could be found. As such the reason being the spectrum of the hydrogen atom is the movement of an electron from one energy level to another.
We can be able to obtain the energy of each of the orbits of the hydrogen atom by the use of;
E = -13.6/n^2
Where n is the principal quantum number.
E = -13.6/(4)^2
E = -0.85 eV
Learn more about Bohr model:https://brainly.com/question/3964366
#SPJ1
When menthol, CH3OH, is burned in the presence of oxygen gas, O2, a large amount of heat energy is released. For this reason, it is often used as a fuel in high performance racing cars. The combination of methanol has the balanced, thermochemical equation CH3OH(g) + 3/2O2(g) — CO2(g) + 2H2O(1) DeltaH= -764Kj How much methanol, in grams, must be found to produce 701 kj of heat?
We have the following balanced equation:
[tex]CH_3OH_{(g)}+\frac{3}{2}O_{2\text{ (g)}}\rightarrow CO_{2\text{ (g)}}+2H_2O_{(l)}[/tex]They also give us the heat of reaction equal to -764 kJ, i.e. it is an exothermic reaction.
By observing the reaction, we can deduce that for this heat to be generated, one mole of methanol is needed. Now let's see how many grams that mole of methanol equals. We will use the molecular weight equal to 32.04 g/mol
[tex]\begin{gathered} g\text{ of methanol = 1 mol }\times\text{ 32.04 g/mol} \\ g\text{ of methanol }=\text{ 32.04 g} \end{gathered}[/tex]Now we know the grams of methanol that generate 764 kJ, because the heat of reaction is directly proportional to the mass of the reactants, we can apply a rule of three to know the grams needed to produce a heat of reaction equal to 701 kJ:
[tex]\begin{gathered} \frac{32.04\text{ g of methanol}}{764\text{ kJ}}=\text{ }\frac{x\text{ g of methanol}}{701\text{ kJ}} \\ x\text{ g of methanol = }\frac{32.04\text{ g of methanol }\times\text{ 701 kJ}}{764\text{ kJ}} \\ g\text{ of methanol = 29.4 g} \end{gathered}[/tex]So, 29.4 g of methanol must be found to produce 701 kJ of heat
Which of the following brings more value to Mussorgsky's work, "Pictures at an Exhibition?"
A. It brought music and art together
B. Many of Hartmann's original pictures no longer exist
C. It complimented Hartmann's work
D. It used a variety of instruments
Mussorgsky dedicated his work Pictures at an Exhibition to a friend, the painter Vladimir Hartmann, who had passed away at the age of 39 at the height of his fame.
What was Modest Mussorgsky's Pictures at an Exhibition inspired by?Mussorgsky through his music, and Hartmann through his images. The Academy of Fine Arts in St. Petersburg organized an exhibition of Hartmann's artwork in 1874. After visiting the exhibit, Mussorgsky was moved to write his piano piece.
Mussorgsky dedicated his work Pictures at an Exhibition to a friend, the painter Vladimir Hartmann, who had passed away at the age of 39 at the height of his fame. The composer and the larger Moscow artistic community were profoundly affected by the loss of both a close friend and an artistic inspiration.
The design of Hartmann's massive, imposing gate, which was intended to honor the fact that Tzar (king) Alexander the II had survived an attempted assassination, served as the inspiration for the Great Gate of Kiev.
Therefore, the correct answer is option C. It complimented Hartmann's work.
To learn more about Hartmann's work refer to:
brainly.com/question/696960
#SPJ4
Burning 1.09g of a fuel causes the water in a calorimeter to increase by 13.6 ∘C. If the calorimeter has a heat capacity of 3.09 kJ/∘C, what is the energy density of the fuel (in kJ/g)?
Please show work! Thanks!
Burning 1.09g of a fuel causes the water in a calorimeter to increase by 13.6 °C. If the calorimeter has a heat capacity of 3.09 kJ/°C, what is the energy density of the fuel is - 38.55 kJ/g.
given that:
c = 3.09 kJ/°C
ΔT = 13.6 °C
heat capacity equation is given by :
q = c ΔT
q = 3.09 kJ/°C × 13.6 °C
q = 42.02 kJ
according to law of conservation of energy sum of heat released by fuel and absorbed by calorimeter is zero
qf + qcal = 0
qf = - q cal = -42.02 kJ
now, The energy density of fuel = - 42.02 kJ / 1.09 g
= - 38.55 kJ/g
Thus, Burning 1.09g of a fuel causes the water in a calorimeter to increase by 13.6 °C. If the calorimeter has a heat capacity of 3.09 kJ/°C, what is the energy density of the fuel is - 38.55 kJ/g.
To learn more about heat capacity here
https://brainly.com/question/22565696
#SPJ1