Here are the answers:
1. False - Molecules is the smallest part of an element that behaves like the element.
2. False - The nucleus contains both protons and neutrons
3. True
4. True
5. A. Nucleus
6. D. Neutron
7. B. Protons and Neutrons
8. C. Electron
9. C. 6
10. C.6
<h2>Answer:</h2><h3>D. ability to react with oxygen</h3><h2>Explanation:</h2>
<em>Im</em><em> </em><em>not</em><em> </em><em>sure</em><em> </em><em>this</em><em> </em><em>in</em><em> </em><em>your</em><em> </em><em> </em><em>choices</em><em> </em><em>but</em><em> </em><em>if</em><em> </em><em>it</em><em> </em><em>is</em><em>,</em><em> </em><em>this</em><em> </em><em>is</em><em> </em><em>the</em><em> </em><em>answer</em><em>. </em>
<em>I</em><em> </em><em>hope</em><em> </em><em>I've</em><em> </em><em>helped</em><em>. </em>
I believe the answer is A
The acceleration of the crate after it begins to move is 0.5 m/s²
We'll begin by calculating the the frictional force
Mass (m) = 50 Kg
Coefficient of kinetic friction (μ) = 0.15
Acceleration due to gravity (g) = 10 m/s²
Normal reaction (N) = mg = 50 × 10 = 500 N
<h3>Frictional force (Fբ) =?</h3>
Fբ = μN
Fբ = 0.15 × 500
<h3>Fբ = 75 N</h3>
- Next, we shall determine the net force acting on the crate
Frictional force (Fբ) = 75 N
Force (F) = 100 N
<h3>Net force (Fₙ) =?</h3>
Fₙ = F – Fբ
Fₙ = 100 – 75
<h3>Fₙ = 25 N</h3>
- Finally, we shall determine the acceleration of the crate
Mass (m) = 50 Kg
Net force (Fₙ) = 25 N
<h3>Acceleration (a) =?</h3>
a = Fₙ / m
a = 25 / 50
<h3>a = 0.5 m/s²</h3>
Therefore, the acceleration of the crate is 0.5 m/s²
Learn more on friction: brainly.com/question/364384
Answer:

Explanation:
For sound waves we have v=d/t where v is the speed of sound and d the distance between the astronauts, while for electromagnetic waves we have c=D/t where c is the speed of light and D the distance between the spaceship and Earth. <em>We have written both times as the same</em> because is what is imposed by the problem, so we have t=d/v=D/c, which means:

And for our values:
