1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
topjm [15]
3 years ago
5

Select the correct answer. Which is true according to the law of conservation of energy? A. In a closed system, the total amount

of energy in the universe keeps on changing. B. The supply of energy is limited, so it is essential to conserve it. C. In a closed system, energy can be created and destroyed. D. In a closed system, energy cannot be used faster than it is created. E. In a closed system, the total energy always remains constant.
Chemistry
1 answer:
mojhsa [17]3 years ago
8 0

in the image there is answer okk

You might be interested in
Attempt 1
Vsevolod [243]

Answer:

12.01

Explanation:

(12.00*98.93% + 13*1.07%) /100% = 12.01

3 0
3 years ago
Millimeters, centimeters, meters, kilometers, Inches,<br> feet, and miles are all examples of
siniylev [52]

Answer:

Distance, some kind of distance or length.

Explanation:

 

4 0
3 years ago
How many half-lives are required for the concentration of reactant to decrease to 1.56% of its original value?4247.56.56
neonofarm [45]

Answer:

6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.

Explanation:

Using integrated rate law for first order kinetics as:

[A_t]=[A_0]e^{-kt}

Where,

[A_t] is the concentration at time t

[A_0] is the initial concentration

Given:

Concentration is decreased to 1.56 % which means that 0.0156 of [A_0] is decomposed. So,

\frac {[A_t]}{[A_0]} = 0.0156

Thus,

\frac {[A_t]}{[A_0]}=e^{-k\times t}

0.0156=e^{-k\times t}

kt = 4.1604

The expression for the half life is:-

Half life = 15.0 hours

t_{1/2}=\frac {ln\ 2}{k}

Where, k is rate constant

So,  

k=\frac {ln\ 2}{t_{1/2}}

\frac{4.1604}{t}=\frac {ln\ 2}{t_{1/2}}

t = 6\times t_{1/2}

<u>6 half-lives are required for the concentration of reactant to decrease to 1.56% of its original value.</u>

6 0
3 years ago
: An unknown metal crystallizes in the cubic crystal structure. The metal has a radius 140pm, atomic mass of 135 g/mol, and dens
ki77a [65]

The cubic unit cell  this metal crystallize as is BCC structure .

<h3> What is unit cell ?</h3>

The structure of a crystalline solid, whether a metal or not, is best described by considering its simplest repeating unit, which is referred to as its unit cell.

The unit cell consists of lattice points that represent the locations of atoms or ions.

The entire structure then consists of this unit cell repeating in three dimensions

\rm \rho =\dfrac{nM}{N_{0} a^{3}} \\\\\\\\\rm n =\dfrac{\rho N_{0} a^{3}}{M} \\\\\\\\Assuming\; it \; to \; be \; a\; BCC\; structure \\\\\\ r = \dfrac{\sqrt{3} \times a}{4} \\\\\\Therefore\; a = 3.23 \times 10^{-8}\\\\\\\\\rm n =\dfrac{13.3 \times 6.022 \times 10^{23}\times 3.23^{3}\times (10^{-8})^{3}}{135} \\\\

n= 2

Hence our assumption was correct

It is a BCC structure .

Therefore the cubic unit cell  this metal crystallize as is BCC structure .

To know more about unit cell

brainly.com/question/13110055

#SPJ1

5 0
2 years ago
How many moles in .5g of sodium bromide?
Genrish500 [490]
I'm not sure how many sign fig's you are required to have.
However I think the final answer would be 0.05 Moles, because of the .5g, that is considered 1 sign fig.

6 0
3 years ago
Other questions:
  • Match each energy source with the correct description
    12·1 answer
  • Why does the nitrogen concentration decrease after hydrogen is added? n2(g)+3h2(g)⇌2nh3(g) why does the nitrogen concentration d
    10·1 answer
  • What would the wavelength of a photon be if its energy is 4.79x10-19 J?
    5·1 answer
  • Question 8 of 10
    9·2 answers
  • For each of these equations, determine the change in the number of moles of gas, δngas.?
    11·1 answer
  • What is the chemical formula for ammonium sulfate?
    5·1 answer
  • Consider this equilibrium for a buffer solution: CH3COOH + H2O CH3COO- + H3O + . When a small amount of acid is added to this sy
    6·1 answer
  • Of the atoms below, __________ is the most electronegative.
    15·1 answer
  • Which phrase explains how a range of fault-block mountains forms? O A. Shear forces cause large earthquakes to happen often and
    5·1 answer
  • A. Energy is transferred to different forms
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!