Answer: 15 grams of magnesium will be present in the magnesium sulfate
Explanation:
According to the law of conservation of mass, mass can neither be created nor be destroyed. Thus the mass of products has to be equal to the mass of reactants. The number of atoms of each element has to be same on reactant and product side.
The balanced chemical reaction is:

As the mass remains conserved at the end of the reaction, there will be 15 grams of Magnesium in magnesium sulphate.
An element is a pure substance which means it cannot be broken down by any means.
Answer:
15000N/m²
Explanation:
Given parameters:
Force exerted by the girl = 450N
Area = 300cm²
Unknown:
Pressure exerted by her feet =?
Solution:
Pressure is the force per unit area on a body;
Pressure =
We need to convert the given area to m²;
10000cm² = 1m²
300cm² =
= 0.03m²
Pressure =
= 15000N/m²
Answer:
the gravitational attraction that exists between all bodies
Explanation:
Comet shoemaker-levy 9 was the comet that broke away and collided with the largest planet on our solar system, the Jupiter. The comet fall apart from the asteroids in the year 1992 and flew and hit Jupiter in the year 1994. This was predicted by the scientist.
Similarly when a comet can hit a planet can be accurately predicted by the scientist or the researcher by understanding and studying the gravitational forces that exists between the bodies in the solar system. It is very important to understand the gravitational attractions which exists between all the bodies in the universe in order to calculate or predict when can a comet collide with a planet.
Lets do process of elimination!
A. Breaking glass - That is a psychical change because if you break it, it is still glass. It didn't change to another substance.
B. Melting ice on a windshield - During the melting process, there is no chemical change, and therefore, no new substance is created.
C. Burning gasoline - When gas burns it usually combines with oxygen to give carbon dioxide, water etc. It is a chemical change.
D. Denting a bumper - The bumper is still a bumper, only thing is it has a dent in it. The properties did not change, meaning no chemical change.