The answer could be a satellite
Explanation:
the correct match can as follows:
1. helium ⇒ discrete atoms (helium is an inert gas)
2. oxygen ⇒ molecules (oxygen exists in molecular form as O2)
3 Magnesium ⇒ matalic lattice ( Magnesium is a metal FCC crystal Structure :) )
4 Aluminum⇒ covalent network (since it is situated in the middle of the group and posses amphoteric properties too)
Buoyant
Buoyancy is the ability to float in fluids.
Gravity is the force of all objects attracted to one.
Friction is the force caused when two objects rub against each other causing them to slow
<span>Archimedes principle explains that the magnitude of that force is proportional to the difference in the pressure between the top and the bottom of the column, and</span> is also equivalent to the weight of the fluid that would otherwise occupy the column, i.e. the displaced fluid.
Negative symbol which means that gain of electron.
I not sure about the answer sorry!! if you will get wrong in your book
When a gamma ray is emitted from the nucleus of an atom it reduces the overall energy of the nucleus. Emission of gamma rays almost happens along with beta and alpha emissions. After the two emissions, the nucleus of the atom would still be in an excited state. To achieve stability, gamma rays are emitted which will decrease the overall energy of the nucleus.