The formular for determinatio of mass number is this:
Mass number = number of proton + number of neutron
From the question, we are told that:
Mass number = 39
Proton number = 19
Number of proton = ?
Number of neutron = mass number - number of proton
Number of neutron= 39 - 19 = 20
Therefore, number of neurtron = 20.
The statement 'a distant star gives off a visible range of light whose color depends on its temperature' is supported by the wave model.
<h3>What is wavelength?</h3>
The wavelength can be defined as the periodic distance of a given wave that repeats in a constant way.
The emissivity of particles is a function of both wavelength and temperature of a given material/object. Visible wavelengths range from 700 nm to 400 nm (violet color).
Star temperature largely determines its color, blue stars are warmer than yellow and red stars, and red stars are cooler than yellow stars.
Learn more about visible wavelengths here:
brainly.com/question/10728818
Imagine that the two atoms are playing tug of war with the electron, but one is pulling with a stronger force than the other. This inequality results in the majority of the rope being pulled toward the stronger atom. In the bond, the electron is pulled closer to the stronger atom too. This results in each side having a partial charge, one being more negative than the other.
Answer:
Air is a mixture of gases. Gas is a state of matter. Hence, air is matter.
Explanation:
See the attached file. It contains a table explaining the composition of air.