Point to be present exactly at midway between center and circumference of circle (let’s say radius = r) should lie at circumference of circle of radius r/2.
Favorable outcome = 2*pi*r/2
Total outcome = Point can be anywhere inside the circle of radius r = Area of circle = pi * r * r
Probability = (2*pi*r/2) / pi * r* r = 1/r.
Not completely sure about correctness . Waiting for comments to verify.
Radium has a half-life of 1500 years. How long will it take for 250kg of Radium to decay down to less than 10kg
Answer:
6967 years
Explanation:
The radioactive substance left after a periodical t year can be expressed by using the formula:
[tex]Q(t) = Q_oe^{-kt}[/tex]
here;
[tex]Q_o[/tex] = the radioactive initial value.
We need to understand that provided that the radioactive substance will get reduced to half of the provided initial amount after a periodic time, Then:
the half-life of the radioactive substance left is:
[tex]Q(h) = \dfrac{Q_o}{2}[/tex]
Given that:
the half-life = 1500 years
[tex]\dfrac{Q_o}{2}= Q_o e^{-k\times 1500} \\ \\ \dfrac{Q_o}{2}= Q_o e^{ -1500k}[/tex]
Divide both sides by [tex]Q_o[/tex]
[tex]\dfrac{1}{2} =e^{-1500k}[/tex]
Then, find the natural logarithm of both side;
[tex]\mathtt{In \dfrac{1}{2} = -1500 k}[/tex]
[tex]k = \dfrac{1}{-1500}\mathtt{In}\dfrac{1}{2}[/tex]
k = 0.000462
So, after a particular (t) time, a 250 kg radium sample was reduced to 10 kg;
Then:
[tex]10 = 250 e^{-0.000462t}[/tex]
[tex]0.04 = e^{-0.000462t}[/tex]
From both sides, finding the natural logarithm, we have:
In(0.04) = -0.000462t
[tex]t = \dfrac{In(0.04)}{-0.000462}[/tex]
t = 6967.26
Thus, it will take approximately 6967 years for a 250 kg radium sample to get reduced to 10 kg.
A sample of a gas has a volume of 852 mL at 298 K. If the gas is cooled to 200K, what would the new volume be?
Answer:
571.81 mL
Explanation:
Assuming constant pressure, we can solve this problem by using Charles' law, which states that at constant pressure:
V₁T₂=V₂T₁Where in this case:
V₁ = 852 mLT₂ = 200 KV₂ = ?T₁ = 298 KWe input the data:
852 mL * 200 K = V₂ * 298 KAnd solve for V₂:
V₂ = 571.81 mLThe new volume would be 571.81 mL.
When 229 J of energy is supplied as heat at constant pressure to 3.0mol Ar(g) the temperature of the sample increases by 2.55K. Calculate the molar heat capacities at constant volume and constant pressure of the gas.
Answer:
The answer is "[tex]\bold{21.616\ \ \frac{J}{mol K}}[/tex]".
Explanation:
when it is a constant pressure:
[tex]Cp= \frac{\Delta q}{n\Delta T} \\\\[/tex]
[tex]=\frac{229}{3\times 2.55}\\\\=\frac{229}{7.65}\\\\=29.93 \frac{J}{mol\ K}\\[/tex]
and,
[tex]Cp-Cv=R\ \ (Mayer's\ formula)[/tex]
then,
[tex]Cv=Cp-R\\\\[/tex]
[tex]=29.93-8.314\\\\=21.616\ \ \frac{J}{mol K}[/tex]
If atoms are electrically neutral then how do they form bonds?
Answer:
The nucleus contains neutrons and protons; protons carry the positive charge. The shells contain electrons which carry the negative charge. So, how can the atom be changed. ... Covalent bonds are electrically neutral because they are not formed due to the transfer of electrons but sharing of electrons.Explanation:
Hope it helps ^-^
#CarryOnLearning
Answer:
When an atom has an equal number of electrons and protons, it has an equal number of negative electric charges (the electrons) and positive electric charges (the protons). The total electric charge of the atom is therefore zero and the atom is said to be neutral. ... Chemically, we say that the atoms have formed bonds
Science- I need help with a question really quick I’m ending school soon
Soap chemical name and chemical formula
plsss help
Answer:
the chemical name for soap is a lot, for example there is Sodium Talowate, Sodium Palmate, and even Sodium Cocoate, but there is more
Explanation:
the chemical formula for it is RCOO-Na+ it has 12 - 18 carbon atoms.
how do the biosphere and geosphere interact? give an example
Answer:
Plants
Explanation:
Plants, part of the biosphere, grow in the soil, which is part of the geosphere
hope this helped :)
Which is the same as moving the decimal point 3 places to the left in a decimal
number?
Multiplying the number by 100
Dividing the number by 1,000
Multiplying the number by 1,000
Dividing the number by 100
Answer:
B. Dividing the number by 1,000
Explanation:
Every time you move the decimal ,add a zero.Since the decimal is moved three times ,there are three zeroes. When you move left ,the number is getting smaller so it is division.
You have made a 2.5 molar solution (2.5 moles per liter) of a particular chemical. If the molecular weight of the chemical is 28 g (28 g/mol), how many kg of the chemical are dissolved in 1 L of this solution
Answer:
Mass of solute in Kg = 0.07 Kg
Explanation:
Given
Molecular weight of the chemical = 28 grams per mole
Solution consists of 2.5 moles of solution
Mass of solute in the solution = 2.5 *28 = 70 grams
Mass of solute in Kg = 70 grams/1000 = 0.07 Kg
If ammonium phosphate reacts with sodium chloride in aqueous solution, what are the products?
Answer:
[tex](NH_4)_3PO_4(aq)+3NaCl(aq)\rightarrow 3NH_4Cl(aq)+Na_3PO_4(aq)[/tex]
Explanation:
Hello there!
In this case, according to the given information, we can set up the appropriate chemical equation when ammonium phosphate reacts with sodium chloride in aqueous solution:
[tex](NH_4)_3PO_4(aq)+NaCl(aq)\rightarrow NH_4Cl(aq)+Na_3PO_4(aq)[/tex]
Which stands for a double replacement reaction, whereby ammonium changes phosphate to chloride and sodium changes chloride to phosphate on the products side. In addition, we can balance the aforementioned equation as shown below:
[tex](NH_4)_3PO_4(aq)+3NaCl(aq)\rightarrow 3NH_4Cl(aq)+Na_3PO_4(aq)[/tex]
Regards!
the means of X ? ⊙_⊙⊙_⊙⊙_⊙
Answer:
x means unknown it is an unknown value.
For example if you have 2 x you have 2 u know values.
Explanation:
If you want us to explain it further please provide a picture.
What is X
Answer:-X mean an Unknown value in a question.
for example :- 2x = 4
→ Here, the value of x is not known but it can be known by solving the problem.
The solution is :-
=> 2x = 4
=> x = 4/2
=> x = 2
So, here the value of X is 2
Hence, we can say that "X is an unknown value in a question and solving that question gives the correct value of x"
-TheExtraterrestrial
what source of electrical energy have scientists been unable to use?
Answer:
Fusion has powered the sun for billions of years.Yet despite decades of effort, scientists and engineers have been unable to generate sustained nuclear fusion here on Earth. In fact, it's long been joked that fusion is 50 years away, and will always be.
Which element has the smallest mass on the periodic table? *
O
H
Pb
He
Mg
Answer:
That should be Hydrogen.
So The second option Is legit!
What is the total mass of products formed when 64.18 grams of CH4 is burned with excess oxygen?
Statement which represents following chemical reaction.
Answer:
Third option is the correct answer
Explanation:
A solution of sodium chloride and a precipitate of barium sulphate is formed.
What did ancient astronomers not know about eclipses?
Answer:
yes of course everyone know eclipse in ancient January 2004 eclipse was founded in other country's
g (2pts) A 10x transfer buffer solution is 250mM Tris and 1.92M glycine. Buffers are always used at 1x concentration in the lab (unless specified otherwise in the protocol), so we will have to dilute the 10x buffer to 1x before use. What is the concentration of Tris and glycine in the 1x buffer
Answer:
The explanation according to the given question is summarized below.
Explanation:
Given:
Tris,
= 250 mM
Glycine,
= 1.92 M
According to the solution,
For the dilution pf 10X to 1X buffer, we get
= [tex]1 \ ml \ of \ 10X \ buffer +9 \ ml \ of \ distilled \ water[/tex]
= [tex]10[/tex]
i.e.,
⇒ [tex]10X \ to \ 1X=1:10 \ dilution[/tex]
Now,
⇒ [tex]10X (250 \ mM\ Tris \ HCl, 1.92M\ Glycine, and\ 1 \ percent (\frac{w}{v} ) SDS) ---->1X(25 \ mM \ Tris \ HCl,0.193 M\ Glycine, and \ 0.1 \ percent(\frac{w}{v} )SDS)[/tex]
A 1.0 kg bottle of sodium carbonate (Na2CO3, 106.0 g/mol) is available to clean up 5.00 liters of spilled concentrated aqueous hydrochloric acid (9.75 M). Is this enough sodium carbonate to neutralize the acid according to the following reaction?
2 HCl (aq) + Na2CO3 (s) 2NaCl (aq) + CO2 (g) + H2O (l)
(1) No, there is approximately 40% too small amount of sodium carbonate needed.
(2) Yes, there is approximately 80% more than what is needed.
(3) No, there is approximately 60% too small amount of sodium carbonate needed.
(4) Yes, there is exactly enough sodium carbonate, but no excess.
(5) No, there is approximately 20% too small amount of sodium carbonate needed.
Answer:
The correct answer is option 4, that is, there is exactly enough sodium carbonate.
Explanation:
Based on the given question, the reaction will be,
2 HCl (aq) + Na2CO3 (s) ⇒ 2 NaCl (aq) + CO2 (g) + H2O (l)
Therefore, for neutralizing 2 moles of HCl, one mole of Na2CO3 is required.
No of moles present in 1 Kg or 1000 grams of Na2CO3 will be,
Moles = Weight/Molecular mass of Na2CO3
Moles = 1000 / 106 = 9.43
Thus, 9.43 moles of Na2CO3 is present.
No of moles present in 1 liter of 9.75 M HCl is 9.75.
No. of moles present in 5 Liters of HCl (9.75 M),
= 5 × 9.75 = 48.75
Thus, for 2 moles of HCl 1 mole of Na2CO3 is required. Now for 48.75 moles of HCl, the moles required of Na2CO3 is 9.75. Therefore, for complete neutralization, the moles of Na2CO3 required is 9.75, and the present moles is 9.43.
Hence, there is exactly enough sodium carbonate.
No links !! No spam !!
1. Which point defect in its crystal units alters the density of a solid?
Please answer
Schottky defects in its crystal units alters the density of a solid!
what is a compound ? Give five examples ?
[tex]\huge\mathsf{\red{\underline{\underline{Compound}}}}[/tex]
[tex]{\green{\dashrightarrow}}[/tex]A chemical compound is a chemical substance that is made of two or more atoms of different elements that share a chemical bond.
[tex]{\green{\dashrightarrow}}[/tex]A chemical formula represents the ratio of atoms per element that make up the chemical compound.
[tex]\large{\pink{\sf{5~ Examples~ of~ Compound~ are:-}}}[/tex]
Example 1 :-Water (H2O, consisting of 2 hydrogen atoms and one oxygen atom)Example 2 :- Carbon dioxide (CO2, consisting of one carbon atom and two oxygen atoms)Example 3 :- Sodium Chloride (NaCl, consisting of one sodium atom and one chloride atom)Example 4:-Methane (CH4, consisting of one carbon atom and four hydrogen atoms)Example 5 :- Pure glucose is a compound made from three elements - carbon, hydrogen, and oxygen. The ratio of hydrogen to carbon and oxygen in glucose is always 2:1:1.
Why will no one help this is bogus
Answer:
D
Explanation:
Why does water have a high cohesion? *
Hydrogen bonding
O It is not known
O Dispersion forces
Answer:
Dispersion forces
that is the answer
I need help with my chemistry but you can oonly choose one option
Answer:
well it is an Synthesis reaction
Explanation:
in the view of the fact that a sodium metal .."Sodium" reacts with an "chloride gas" to form a sodium Chloride. NaCL2NaCl-->2Na+ Cl2
Correct Option- Decomposition
_____________________________
Decomposition reactions are those reactions in which a compound breaks or splits into two or more simpler substances. In such reactions, one reactant breaks down to form many i.e. at least two products. These reactions require energy to break existing bonds, so they take place in the presence of heat, light, or electricity.
Example:- AB--> A+B
Hope This Helps You ❤️Interpreting Velocity vs. Time Graphs
Velocity vs Time
Use the information presented in the graph to answer
the questions,
Which segments show acceleration?
Which segment indicates that the object is slowing
down?
What is the velocity of segment B?
What is the acceleration of segment B?|
50
B
40
30
Velocity (m/s)
20
А
10
0
8 9 10
1 2 3 4 5 6 7
Time (s)
Answer:first part is A and C, second part is C, third part is 40 m/s and the fourth part is zero
Explanation: I guessed and got them right lol
Calculate the mass of oxygen in 30 g of CH NH COOH?
Molar mass of CH2NH2COOH - 75
Given mass of CH2NH2COOH - 30
Moles of CH2NH2COOH = Given mass/ Molar mass
moles of CH2NH2COOH = 30/75 = 0.4 mol
One mole of CH2NH2COOH contains 32 gram of oxygen
0.4 mole of CH2NH2COOH will contain = 0.4 × 32= 12.8 g of oxygen
Answer- the mass of oxygen in 30 g of CH2NH2COOH is 12.8 gram!
The mass of oxygen in 30 g of CH₂NH₂COOH is 12.8 g.
We'll begin by calculating the mass of 1 mole of CH₂NH₂COOH and the mass of oxygen in the compound.
1 mole of CH₂NH₂COOH = 12 + (2×1) + 14 + (2×1) + 12 + 16 + 16 + 1 = 75 g
Mass of oxygen in CH₂NH₂COOH = 16 + 16 = 32 g
Thus,
75 g of CH₂NH₂COOH contains 32 g of Oxygen.
With the above information, we can obtain the mass of oxygen in 30 g of CH₂NH₂COOH. This can be obtained as follow:
75 g of CH₂NH₂COOH contains 32 g of Oxygen.
Therefore,
30 g of CH₂NH₂COOH will contain = (30 × 32) / 75 = 12.8 g of Oxygen.
Thus, 12.8 g of Oxygen is present in 30 g of CH₂NH₂COOH
Complete question:Calculate the mass of oxygen in 30 g of CH₂NH₂COOH.
Learn more about mass composition:
https://brainly.com/question/11617445
scenario Juan and Maria Lopez wish to invest in a no-risk savings account. They currently have 530,000 in an account bearing 5.25 % annual interest, compounded continuously. The following options are available to them.
Answer:
The amount after three year is 617934.1302
Explanation:
Complete question
A person places $530,000 in an investment account earning an annual rate of 5.25%, compounded continuously. Using the formula V = Pe^{rt}V=Pe rt , where V is the value of the account in t years, P is the principal initially invested, e is the base of a natural logarithm, and r is the rate of interest, determine the amount of money, to the nearest cent, in the account after 3 years
Solution
The formula for calculating compound interest is
[tex]A = p (1 + \frac{r}{n})^{nt}[/tex]
Substituting the given values we get -
[tex]A = 530,000 (1 + \frac{5.25}{100})^3\\A = 530,000 * ( 1+ 0.0525)^3\\A = 530,000 * ( 1.0525)^3\\A = 617934.1302[/tex]
The amount after three year is 617934.1302
Hydration of alkynes gives good yields of single compounds only with symmetrical or terminal alkynes. Draw the major organic product(s) formed when 3-methylcyclodecyne undergoes hydration in the presence of HgSO4 and H2SO4.
Answer:
Following are the solution to the given choice:
Explanation:
Hex-2-yne is just not alkyne symmetric, therefore two things respectively hexan-3-one and hexan-2-one are to be given.
The attached file it displayed the response along with the mechanism, please find the.
When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH versus volume of NaOH added) increases when sodium hydroxide is first added. This change shows that ________
Answer:
When an acetic acid solution is titrated with sodium hydroxide, the slope of the titration curve (pH versus volume of NaOH added) increases when sodium hydroxide is first added. This change shows that acetic acid is being converted to sodium acetate.
Explanation:
ABOUT TITRATION - Titration is a chemical analysis method for determining the amount of a constituent in a sample by adding an exact known quantity of another substance to the measured sample with which the desired constituent reacts in a specific, known proportion. A burette, which is essentially a long, graduated measuring tube with a stopcock and a delivery tube at the bottom end, is used to gradually administer a standard solution of titrating reagent, or titrant.
It is feasible to identify a good visual color indicator for many titration processes that will signify the end point at, or very near to, the equivalence point.
Acid-base titrations, precipitation titrations, complex-formation titrations, and oxidation-reduction (redox) titrations are examples of such titrations, which are categorised according to the nature of the chemical reaction that occurs between the sample and the titrant.
Titrations of metal ions with the reagent disodium ethylenediaminetetraacetate are the most important titrations based on complex-formation processes (a salt of edetic acid, or EDTA).
Hence , the answer is that acetic acid is converted into sodium acetate.
How it affects your lives or the lives of people near the area where soil erosion happened?
Please Answer! thanks!
Answer:
negatively
Explanation:
when soil erosion happens,by the agent of water for example,the soil will eventually lose it's valuable minerals and become infertile, people won't be able to grow crops there.
A science lab has copper wire coated
with rubber tubing, a plastic vial, and a
pair of cotton gloves. Which of these
materials is not an electrical insulator?
Answer:
the answer is copper wire