Answer: The temperature is there to confuse you on purpose. Density changes with temp, but in these type of problems, they mean nothing
Explanation:
The formula for density is mass per unit of volume.

We dont have to do any conversions here so it boils down to division and multiplication.

Now for the second part:

Density is typically the best way to determine the chemical property because almost always it is unique.
Answer: star
Exoplanets are the planets present in the other star system. There are billions of stars in our galaxy and we expect presence of other planetary systems similar to our solar system. Exoplanets can be detected by a) radial velocity method b) astrometric method c) transient method. In the radial method, we observe the changes in the spectrum of the light coming from star when an exoplanet is orbiting it. There is change in gravitational pull as the planets goes around the star. It sometimes pulls into smaller orbit. like this the star wobbles back and forth. By measuring the blueshift and redshift in the star's spectrum, exoplanet can be discovered.
Answer is: line be long 3,011·10¹³ kilometers.
diametar of virus = 5·10⁻⁶ cm ÷ 100000 = 5·10⁻¹¹ km.
line lenght = 5·10⁻¹¹ km · 6,023·10²³.
line lenght = 3,011·10¹³ km.
Avogadro number = 6,023·10²³.
1 cm = 10⁻² m = 10⁻⁵ km.
Phương trình hóa học: 2Mg+O2->2Mgo