Planet z is 5000 km in diameter. the free-fall acceleration on planet z is 7.0 m/s2. part a what is the mass of planet z? express your answer using two significant figures. m = kg submitmy answersgive up part b what is the free-fall acceleration 9000 km above planet z's north pole? express your answer using two significant figures.

(a)g = Gm/r^2
where G=6.67 * 10^-11 Nm^2/kg^2,
m is the mass of the planet,
r is the radius of the planet. 
7.0 = (6.67 * 10^-11)/(2500^2) * m
m= (25000000^2 * 9.0)/(6.67 * 10^-11) 
m = 8.4333 x 10^24 kg
(b) g=Gm/r^2. This time, the radius is 2500+10000 = 12500km g = (6.67 * 10^-11 * 8.43333*10^18)/(12500^2) 

g = 3.6 m/s^2 

Atoms are the thing that make up molecules and compounds. Molecule. Two or more atoms joined together with covalent bonds. Molecules contain two or more atoms and are held together by covalent bonds, whereas compounds are held together by ionic bonds. Compound. Two or more elements bonded together through ionic attraction.