Answer:
E = 147000 J
Explanation:
Given that,
The mass of meteor, m = 50 kg
The altitude of the meteor, h = 300 m
We need to find the potential energy of the meteor. The formula for the potential energy is given by :

Put all the values,

So, the required potential energy is equal to 147000 J.
The ion composition of Magnesium is 12,10, 2+.
Magnesium is a chemical element with symbol Mg and an atomic number 12, it has 12 protons, and 12 electrons with a chemical configuration of 2:8:2. It requires to loose two electrons to form a stable configuration forming a cation (positively charged ion) with a charge of +2 and a configuration of 2:8 ( 12 protons and 10 electrons).
Answer: for an object or gas or liquid to float in another there must be a difference in density
Explanation:
Helium has a density of 0.18 kg/m³ and air has a density of 1.29 kg/m^³. If a balloon is filled with helium it will float in air due to density differences
Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially submerged, is equal to the weight of the fluid that the body displaces
Actually, there are only about 100 atoms that have been yet discovered. But each element has many different kinds of atom. For instance, carbon. Do you know carbon has more than 30 or 50 different types of atoms? Well, how? There are isotopes. Don't think that there is only one carbon atom which has 6 electrons and 6 protons and 6 neutrons. There are more. C-13 has 6 electrons and 6 protons and 7 neutrons. While, C-14 has 6 electrons and 6 protons and 8 neutrons. I just showed you three stable isotopes of carbon(element). But, what is really an isotope?? Did you notice that all of these atoms had the same number of protons and electron but different numbers of neutrons? This is really an isotope. Well, if an atom takes a few more electrons or gives off a few electrons, it still stays the same element/ atom type. Just like that an element can have atoms of different neutron number. It may be less or more. It doesn't affect the atom much: just makes an isotope. But it does affect the atomic mass number or radioactivity of an atom. So, an element can have many different forms of isotopes of its atoms. In this way, being only 100 atoms, there can 1000 atoms or (more than that!).
To make it more clear-
Definition of ISOTOPE: <span>any of two or more forms of a </span>chemical<span> element, having the same number of protons and electrons in the nucleus, or the same atomic number, but having different numbers of neutrons</span>
HOPE YOU UNDERSTOOD THE MATTER:-))
J.J Thompson’s model shows a sphere with electrons that are moving around freely. However, Thompson’s model does not show protons or neutrons. The model that we have today gives a clearer structure showing protons, neutrons, and electrons inside an atom.