Explanation:
its hard to explain unless we know what the question fully asks..
Imagine the following scenario involving marbles as "radioactive isotopes".
Let's say the half-life of green marbles is 1 million years.
In one hand, you're holding 2 green marbles. In your other hand, you're holding 500,000 green marbles.
Hypothetically, noting that we have two different starting amounts of "isotopes", how long will it take for half of each amount to decay?
Answer:
1 million years
Explanation:
The half life of a radioactive isotope refers to the time it takes for the radioactive isotope to decay to half of its original amount.
The half life of a radioactive isotope is independent of the amount of starting material. Hence, whether the amount of starting material is small or large, the half life of the substance remains the same.
Hence the half life of 2 green marbles and 500,000 green marbles is 1 million years.
keeping a bike indoor will stop it rusting true or false
Answer: True because if you leave it outside and it rains on the bike it will cause rust. Keep it in the garage or something. :) I have a bike btw.
Explanation:
The best way to prevent rusting is to store your bike safely away when it isn't being used and apply a rust-proofing lubricant to protect it when you are riding it – enjoying those wet and wild rides guilt-free!
so true
what is the major organic product obtained from the following sequence of reactions Br Li Et2O CH2I2 Zn(Cu)
Answer: Hello the complete question showing the sequence is attached below
answer : Option C ( cyclopropane )
Explanation:
The Major organic product obtained from the following sequence of reactions attached below is : cyclopropane
from the sequence of reactions the first product will be lithiated alkaline and it will react with Cu to form Gilman reagent while the Gilman reagent will now react with alkene iodide to form cis alkene . major organic product that would be obtained when cis alkene reacts with Simmons smith reagent will be Cyclopropane
attached below is the detailed description of the products and the major organic product
Give an example of a model used in Earth science. Explain why models are particularly important to this field.
Answer:
Some examples include maps and globes. Conceptual Models - These models serve as a tool to piece together a variety of concepts together so that we can better conceptualize the phenomena under investigation.
Scientific models are used to explain and predict the behaviour of real objects or systems and are used in a variety of scientific disciplines, ranging from physics and chemistry to ecology and the Earth sciences
Pure gold has a density of 19.3 g/cm³. if it is made into a crown. what will be the density of the crown? how can you find out if the crown is indeed made of pure gold and nothing else?
Answer:
19.3g cm^3
If it deviates from the original 19.3g cm^3
An alternating current complete 100 cycles in 0.1s. it's frequency is
Answer:
The frequency is 1000 cycles/s
Explanation:
An alternating current is an electrical current in which the current changes its magnitude and the sense cyclically. The frequency of this current is defined as the cycles that the current completes in one second.
As the current completes 100 cycles in 0.1 seconds, the frequency is:
100 cycles / 0.1s = 1000 cycles /s
The frequency is 1000 cycles/sWhich of the following limits a population's growth?
Answer:
hereeee
Explanation:
Limitations to population growth are either density-dependant or density-independent. Density-dependent factors include disease, competition, and predation. Density-dependant factors can have either a positive or a negative correlation to population size.
Answer: environmental factors
Explanation:
40 POINTS!!! Ice at 0.0 degrees C is combined with 50.0g of water at 75.0 degrees C. Calculate the grams of ice present initially if the entire mixture comes to a final temperature of 25.0 degrees C after the ice melts. Specific heat of water is 4.18 J/goC. SHOW WORK!
Answer:
mi = 31.28 g
Explanation:
According to the law of conservation of energy:
[tex]Heat\ Gain\ by\ Ice = Heat\ Lost\ by\ Water\\m_iL = m_wC\Delta T\\[/tex]
where,
mi = mass of ice = ?
L = Latent heat of fusion of ice = 334 J/g
mw = mass of water = 50 g
C = specific heat of water = 4.18 J/g.°C
ΔT = change in temperature of water = 75°C - 25°C = 50°C
Therefore,
[tex]m_i(334\J/g) = (50\ g)(4.18\ J/g.^oC)(50^oC)[/tex]
mi = 31.28 g
What is the mass in grams of precipitate formed when 250.0 mL of 0.360 M ZnCl₂ is mixed with excess KOH in the following chemical reaction?
ZnCl₂ (aq) + 2 KOH (aq) → Zn(OH)₂ (s) + 2 KCl (aq)
Answer:
8.95 g
Explanation:
ZnCl₂ (aq) + 2 KOH (aq) → Zn(OH)₂ (s) + 2 KCl (aq)First we calculate how many ZnCl₂ moles reacted, using the given concentration and volume:
250 mL / 1000 = 0.250 L0.360 M * 0.250 L = 0.090 mol ZnCl₂Then we convert ZnCl₂ moles into Zn(OH)₂ moles [ Zn(OH)₂ is the precipitate, as it is the solid]:
0.090 mol ZnCl₂ * [tex]\frac{1molZn(OH)_2}{1molZnCl_2}[/tex] = 0.090 mol Zn(OH)₂Finally we convert 0.090 Zn(OH)₂ moles into grams, using its molar mass:
0.090 mol Zn(OH)₂ * 99.424 g/mol = 8.95 gThe mass of a substance is the product of the molar mass and the moles of the substance. The mass of precipitate formed in the reaction is 8.95 gm.
What is Mass?The mass of the substance is the weight of the compound or the molecule present in the sample.
The balanced chemical reaction is shown as:
[tex]\rm ZnCl_{2} (aq) + 2 KOH (aq) \rightarrow Zn(OH)_{2} (s) + 2 KCl (aq)[/tex]
Given,
Volume (V) of zinc chloride = 0.250 L
Molarity of zinc chloride (M) = 0.360M
Moles of zinc chloride are calculated as:
[tex]\begin{aligned} \rm moles &= \rm molarity \times volume \\\\&= 0.360 \times 0.250\\\\&= 0.090 \;\rm mol\end{aligned}[/tex]
Moles of zinc hydroxide from zinc chloride are calculated as:
[tex]0.090\;\rm mol \; ZnCl_{2} \times \dfrac{ 1\;\rm mol \;\rm Zn(OH)_{2}}{1\;\rm mol\; ZnCl_{2}} = 0.090 \;\rm mol[/tex]
Mass is calculated as:
[tex]\begin{aligned} \rm mass &= \rm moles \times molar \; mass\\\\&= 0.090 \times 99.424 \\\\&= 8.95 \;\rm gm\end{aligned}[/tex]
Therefore, 8.95 gm precipitate is formed.
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CHEMISTRY HELP ASAP
Use this balanced equation for the two questions below:
2KClO3(s) → 2KCl(s) + 3O2(g)
9. How many moles of KClO3 are used to produce 9.9 moles of O2?
10. How many moles of O2 are produced from 11.2 moles of KClO3?
PLS SHOW WORK TOO THX
Answer:
1 mole of KClO_3 contains 3 moles of O.
10 moles of O_2 contains 20 moles of O.
You need 20/3 moles of KClO_3 to produce 10 moles of O_2
Explanation:
sana makatulong
A change In which properly of light will have no effect on whether or not the photoelectric effect occurs
Answer: intensity is the answer. Intensity has no affect on whether or not the photoelectric effect occurs.
Explanation:
Chemistry question balance equations
Answer:
I don't understand this question
What determines the degree of polarity in a bond?
Answer:
The relative electronegativity of the two bonded atoms determines the polarity of a bond. If the difference in electronegativities between the two atoms is less than 0.4, the bond is nonpolar covalent. ... If the difference in electronegativities between the two atoms is more than 2.0, the bond is ionic.
A 36.6-mol sample of Co represents how many atoms?
Answer:
2.20 x 10²⁵ atoms
Explanation:
Atoms of CO= 36.6-mol sample
From Avogadro's constant, which is
(6.022 × 10^ 23 atoms per mole)
Then
Number of atoms=[ 6.022 × 10^ 23 atoms/mole] × [36.6-mol]
= 2.20 x 10²⁵ atoms
Hence, number of atom is 2.20 x 10²⁵ atoms
Steve and Meg are doing an experiment where they need to make 37 grams of Fe2O3. How many grams of Fe would they need ?
Answer:
25.9g
Explanation:
Molecular mass of Fe₂O₃ = (56 * 2) + (16 * 3)
= 112 + 48 = 160
Let's follow the unitary method now
In 160g Fe₂O₃ , there is 112 g Fe
In 1 g Fe₂O₃ , there is 112 / 160 g Fe
In 37 Fe₂O₃ , we need 112 * 37 / 160
= 25.9 g Fe
AN object has a volume
of 77ml and a mass of
429. What is the density
of this object?
Answer:
4.254320865115cm or simplied 4.25cm
Explanation:
The molar mass of two equally sized samples of unknown gaseous compounds is shown in the table.
Molar Mass Comparison
Gas Molar Mass
X 28 g/mol
Y 44 g/mol
At STP, which describes the density and effusion of both gases? (4 points)
a
Gas X has a higher density and effuses faster than Gas Y.
b
Gas X has a higher density and effuses slower than Gas Y.
c
Gas X has a lower density and effuses slower than Gas Y.
d
Gas X has a lower density and effuses faster than Gas Y.
Answer:
D. Gas X has a lower density and effuses faster than Gas Y.
Explanation:
I took the test.
Lower Density = effuse/ diffuse fasterLower Molar Mass = effuse/ diffuse fasterGas X has a lower density and effuses faster than Gas Y. Hence, option D is correct.
What is density?Density is the amount or the number of entities that can be contained in an area. It is denoted by ρ and is calculated as,
ρ = Mass ÷ Volume
Diffusion is the process of movement of a substance from the area of higher concentration to the area of lower concentration.
Effusion is the process of a gas being poured out through a hole diametrically smaller than the structural exit of the container.
The gas with a smaller mass will diffuse slower in rate than the gas with a higher mass.
Hence, Gas X has a lower density and effuses faster than Gas Y.
Learn more about density here:
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Question - Complete and balance the following chemical equations:
C8H18 + O2 --->
When you complete and balance the specific equation, give the following information:
State which type of chemical reaction this is.
Explain how you know which type of chemical reaction it is.
List the amount of each element you have when the equation is unbalanced. E.g. there is one mole of calcium on the reactants side.
Give the balanced chemical equation.
List the amount of each element you have when the equation is balanced.
The order of the elements that you balanced the equation with.
Explain how you know which coefficient to use for the specific compound.
Your Answer:
Answer:
2C8H18 + 25O2 -> 16CO2 + 18H2O
(16C, 36H, 50O)
H2O requires 2H per H2O, Meaning that you'd have 9H2O's from 1C8H18, but you still need that O2 for the CO2 and because the reactant side has 8C (within C8H18) You'd have to times the amount of required O2 from CO2 by 8. Even then you still don't have enough for both CO2 and H2O so you'll have to multiply MORE causing a bigger chain reaction resulting in 2C8H18 + 25O2 -> 16CO2 + 18H2O
Help i just need people to answer the question today
Answer:
1) Hydrogen
2) Methane
3) Carbon
4) Structural isomer
5) Ethene also known as ethylene
6) Hydrocarbons are widely used as fuel
7) Crude oil
Explanation:
Every force has a what?
Answer:
What do you mean Every force has a what?
Answer:
The statement means that in every interaction, there is a pair of forces acting on the two interacting objects. ... The direction of the force on the first object is opposite to the direction of the force on the second object. Forces always come in pairs - equal and opposite action-reaction force pairs.
3. Are the gates working and can be easily opened in case of
emergency?
Answer:
Yes, I think.
Explanation:
You cannot make an emergency door if you cannot open it easily. So if there is an emergency you need to be able to go threw it fast. So if there is a fire and you needed to just get out of there through the emergency door, just open it and you can get out.
The gates of an emergency exit must be easily opened in case of an emergency to let people out of the building.
It is required that building ought to have an emergency exit. The emergency exit is a door that can easily be opened so that people can leave via that door.
Hence, the gates of an emergency exit must be easily opened in case of an emergency to let people out of the building.
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Why does the N2 molecule in this room have a greater average velocity
than the O2 molecules in the same room?
Answer:
Explanation:
The temperature will only move the average velocity of all the molecules in the room. There is a limitation. The O2 molecules are heavier than the N2 molecules. The lighter the molecules, the faster they are going to move on average.
1. How is the law of conservation of mass shown by a balanced chemical equation?
A) The subscripts must be the same on both sides of the equation.
B) The total volumes of the substances must be the same on both sides of the equation.
C) The coefficients must be the same on both sides of the equation.
D) The number of each type of atom must be the same on both sides of the equation.
Answer:
D
Explanation:
hope this helps
Which is the limiting reactant?
Answer:
Explanation:
The limiting reactant (or limiting reagent) is the reactant that gets consumed first in a chemical reaction and therefore limits how much product can be formed.
Compute the mass of KI needed to prepare 500 mL of a 0.750 M solution.
Answer:
62 grams
Explanation:
Molarity=mol/liter
We have mL and Molarity
500 mL * 1 L/1000 mL=0.5
Plug 0.5 in and solve for moles
0.75=mol/0.5
0.75*0.5=0.375 mol
Convert to grams by finding the mass of KI: 39+126.9= 165.9 grams
0.375 mol KI * 165.9 grams KI/1 mol KI= 62.2125 grams
The mass of KI needed is 124.5 grams, this can be calculated by adding the values in molarity formula.
What is Molarity?It is defined as number of moles of solute over volume of solution in liters.
It is given by:
M = n/ V
What information do we have?
Molarity= 0.750 M
Volume = 500 mL= 1 L
Molar mass of KI = 166 g/mol
To find:
Mass of KI=?
On substituting the values:
M= n/V
0.750 M= n/ 1 L
n= 0.750 M* 1l
n= 0.750 moles
Number of moles is the ratio between mass and molar mass.
n= m/M
0.750 moles = m/ 166 g/mol
m= 0.750*166
m= 124.5 grams.
Thus, the mass of KI needed is 124.5 grams.
Find more information about Molarity here:
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How many moles of OH−(aq) (hydroxide ions)are present in the balanced redox reaction?
NO3−(aq) + ClO−(aq) + H2O(l) → NO(g) + ClO2−(aq) + OH−(aq)
The molecular weight (MW) of CuSO4 is 250g/mol. How many grams of CuSO4 are needed to make a 10 ml solution that has a molarity of 2.0 M?
Answer:
Explanation:
(The MW of CuSO4 is 250 g/mol).
Answer:
5 grams of CuSO4
Explanation:
First you make a stoichiometric relationship between the molarity and liters. So there is 2 mols per every liter. Then you put in the moleculur weight( for every mol there is 250 g). Then you have to get rid of the liters, so you times the equation by 0.01(this was found by 10ml converted into liters). After all of that you should end up with 5 grams of CuSo4
Because a water molecule has a negative end and a positive end it displays?
Answer:
A water molecule displays polarity by having negative and positive ends. Due to this charge difference, a water molecule is called a dipole.
Explanation:
Show the work. Convert 150 mm Hg to psi.
pls help me, thanks
Answer:
2.9 psi
Explanation:
Pressure (mmHg) = 150 mmHg
Pressure (psi) =?
The pressure in pound per square inch (psi) can be obtained as follow:
51.715 mmHg = 1 psi
Therefore,
150 mmHg = 150 mmHg × 1 psi / 51.715 mmHg
150 mmHg = 2.9 psi
Thus, pressure in pound per square inch (psi) is 2.9 psi.
Look at the diagram. Which shows the correct arrangement of electrons in water?
Answer:
Option 4
Explanation:
In water molecule, oxygen has -2 charge on it while the hydrogen has +1 charge and one atom of oxygen combines with two hydrogen atoms. A hydrogen need only two electrons to complete its octet (one electron is its own the second electron is shared by oxygen) and a oxygen needs 8 electrons (It has six of its own and two are shared by two hydrogen atom).
Hence, option 4 is correct
Answer:
Option 2
It's more balanced than the others