Compounds. two or more compounds.
Explanation:
Exothermic reaction are those in which heat releases during a reaction
The wavelength is 2m.
Hence, Option c) 2m is the correct answer
Given that;
Frequency;
Speed; 
Wavelength; 
using the expression for the relations between wavelength, frequency and speed of wave:

Where
is wavelength, f is frequency and v is speed.
We substitute our given values into the equation

The wavelength is 2m.
Hence, Option c) 2m is the correct answer.
To learn more about wavelength, click here: brainly.com/question/1347107
Answer:
400 g
Explanation:
The computation of the number of grams in the original sample is shown below:
Given that
half-life = 5.26 years
total time of decay = 15.8 years
final amount = 50.0 g
Now based on the above information
number of half-lives past is
= 15.8 ÷ 5.26
= 3 half-lives
Now
3 half-lives = 1 ÷ 8 remains = 50.0 g
So, the number of grams would be
= 50.0 g × 8
= 400 g
Answer:
The nearest plant (A) receives 4 times more radiation from the farthest plant
Explanation:
The energy emitted by the star is distributed on the surface of a sphere, whereby intensity received is the power emitted between the area of the sphere
I = P / A
P = I A
The area of the sphere is
A = 4π r²
Since the amount of radiation emitted by the star is constant, we can write this expression for the position of the two planets
P = I₁ A₁ = I₂ A₂
I₁ / I₂ = A₂ / A₁
Suppose index 1 corresponds to the nearest planet,
r2 = 2 r₁
I₁ / I₂ = r₁² / r₂²
I₁ / I₂ = r₁² / (2r₁)²
I₁ / I₂ = ¼
4 I₁ = I₂
The nearest plant (A) receives 4 times more radiation from the farthest plant