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
MakcuM [25]
3 years ago
13

When determining whether a chemical reaction has taken place, you observe and look for several indicators. Which would be consid

ered an indication that a chemical reaction or chemical change has taken place? A) Solid melts. B) Heat is given off. C) Substance dissolves D) Substance changes shape.
Physics
1 answer:
Inga [223]3 years ago
6 0
The answer is B.

A cannot be the answer is melting is a physical change. No chemical reaction took place.

B is the answer as it is a EXOTHERMIC REACTION so heat will be given off.

C cannot be the answer as dissolving is basically atoms becoming ions, not a chemical reaction whereby a reactant reacts with another reactant to form a product.

D cannot be the answer. Same reason as for why A is not the answer.

Cheers.
You might be interested in
A rough estimate of the radius of a nucleus is provided by the formula r 5 kA1/3, where k is approximately 1.3 × 10213 cm and A
Sphinxa [80]

Answer:

Density of 127 I = \rm 1.79\times 10^{14}\ g/cm^3.

Also, \rm Density\ of\ ^{127}I=3.63\times 10^{13}\times Density\ of\ the\ solid\ iodine.

Explanation:

Given, the radius of a nucleus is given as

\rm r=kA^{1/3}.

where,

  • \rm k = 1.3\times 10^{-13} cm.
  • A is the mass number of the nucleus.

The density of the nucleus is defined as the mass of the nucleus M per unit volume V.

\rm \rho = \dfrac{M}{V}=\dfrac{M}{\dfrac 43 \pi r^3}=\dfrac{M}{\dfrac 43 \pi (kA^{1/3})^3}=\dfrac{M}{\dfrac 43 \pi k^3A}.

For the nucleus 127 I,

Mass, M = \rm 2.1\times 10^{-22}\ g.

Mass number, A = 127.

Therefore, the density of the 127 I nucleus is given by

\rm \rho = \dfrac{2.1\times 10^{-22}\ g}{\dfrac 43 \times \pi \times (1.3\times 10^{-13})^3\times 127}=1.79\times 10^{14}\ g/cm^3.

On comparing with the density of the solid iodine,

\rm \dfrac{Density\ of\ ^{127}I}{Density\ of\ the\ solid\ iodine}=\dfrac{1.79\times 10^{14}\ g/cm^3}{4.93\ g/cm^3}=3.63\times 10^{13}.\\\\\Rightarrow Density\ of\ ^{127}I=3.63\times 10^{13}\times Density\ of\ the\ solid\ iodine.

7 0
3 years ago
What is the acceleration of the object?<br> m/s²
Orlov [11]

Answer:

-2.5m/s^2

Explanation:

10-40/12-0=-2.5

7 0
2 years ago
A solenoid 50-cm long with a radius of 5.0 cm has 800 turns. You find that it carries a current of 10 A. The magnetic flux throu
ioda

Answer:

126 mWb

Explanation:

Given that:

length (L) = 50 cm = 0.5 m, radius (r) = 5 cm = 0.05 m, current (I) = 10 A, number of turns (N) = 800 turns.

We assume that the magnetic field in the solenoid is constant.

The magnetic flux is given as:

\phi_m=NBAcos(\theta)\\Where\ B\ is\ the\ magnetic\ field\ density,A\ is \ the\ area.\\But\ B =\mu_onI.\ n \ is\ the\ number\ of\ turns\ per\ unit \ length=N/L\\Therefore,B=\frac{\mu_oNI}{L} \\substituting\ the\ value\ of\ B\ in\ the\ equation: \\\phi_m=\frac{NAcos(\theta)*\mu_oNI}{L} .\ But \ \theta=0,cos(\theta)=1\ and\ A=\pi r^2\\ \phi_m=\frac{N^2\pi r^2\mu_oI}{L} \\Substituting\ values:\\\phi_m=\frac{800^2*(\pi*0.05^2)*(4\pi*10^{-7})*10}{0.5}=0.126\ Wb=126\ mWb

8 0
3 years ago
What is the weight of a pumpkin with a mass of 5 kg? kk
pav-90 [236]

Explanation:

actually, the question would need to give you what is the gravitational force, so let's take the average of the gravitational for me which is 10 N /kg

and the formula for finding weight is

W = mg

W = (5)(10)

W = 50 N

hope it is helpful, if not please report it so that someone else gets to try

please vote

4 0
3 years ago
Photosynthesis is a chemical reaction where carbon dioxide and water react to form glucose (C6H12O6) and oxygen gas. Which repre
AnnyKZ [126]
<span>Correct Answer: D) 6CO2 + 6H20 → C6H12O6 + 6O2</span>

The reactants are Carbon Dioxide (CO2) and Water (H2O) and the products are Glucose (C6H12O6) and Oxygen gas (O2).

In a balanced chemical equation, the number of atoms of each element are same on both left and right hand side of the equation. 

In the given options, option D gives the balanced chemical equation and mentions the reactants and products on correct sides of the equation. So the correct answer is Option D
3 0
3 years ago
Read 2 more answers
Other questions:
  • You attach a 1.10 kg block to a horizontal spring that is fixed at one end. You pull the block until the spring is stretched by
    8·1 answer
  • True or false a solid object can cast a shadow
    15·2 answers
  • One of your summer lunar space camp activities is to launch a 1090 kg rocket from the surface of the Moon. You are a serious spa
    8·1 answer
  • An antigen is a protein made by your body to respond to a specific foreign molecule.
    14·1 answer
  • 3 similar things between HIIT,CrossFit y Bodyweight
    14·1 answer
  • YALLL I NEED HELP ASAP... THIS DUE AT 11:59 AND ITS 10.42 RIGHT NOW
    12·1 answer
  • When is a train on Earth in motion relative to the sun? A It is relative to the sun only when the train is not moving. B It is n
    13·1 answer
  • Total distance divided by total time
    14·1 answer
  • If a roller coaster cart, with a mass of 100 kg, traveled this coaster, how much kinetic energy would it have at point 'E'?
    10·1 answer
  • The name of the bright star near the center that the other stars appear to be circling is:
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!