Halogens<span> are extremely reactive elements because they need one more electron to gain a full octet of valence electrons, whereas the </span>noble gases<span>are extremely unstable because they already have their full octet.</span>
Sound waves are longitudal waves meaning they go back and forth
Stars are formed in <u>nebulas</u>, interstellar clouds of dust and gas.
Answer:
+16 J
Explanation:
We can solve the problem by using the 1st law of thermodynamics:

where
is the change of the internal energy of the system
Q is the heat (positive if supplied to the system, negative if dissipated by the system)
W is the work done (positive if done by the system, negative if done by the surroundings on the system)
In this case we have:
Q = -12 J is the heat dissipated by the system
W = -28 J is the work done ON the system
Substituting into the equation, we find the change in internal energy of the system:

Answer:
Real image
Explanation:
The picture is real, but it is reversed and tiny. An picture generated by a pinhole camera has certain features. As compared item, the image created by a pinhole camera is normally pretty small and looks reversed both on the vertically and horizontally axis.