Answer:
C. Both observation 1 and observation 2.
Explanation:
The heliocentric model states that the Earth and planets revolve around the Sun at the center of the Solar System.
Observation 1 was answered by Nicolas Copernicus, father of the heliocentrism, in 1543. The reverse effect is an illusion created because the Earth revolves faster around the Sun than Mars.
And observation 2 also is explained by the model because the rotation of the earth made that the Stars be closer to it at different times of the year.
I hope this answer helps you.
Dissolver is the answer i think because that is what disovling means
Answer:
C.
Explanation:
Exothermic means the energy of products is lower than energy of reactants. Transition state will always be the highest energy among the two.
<span>He discovered that every atom contains a nucleus where all of its positive charge and most of its mass are concentrated</span>
MgF₂ has one magnesium ion and two fluoride ions per unit of magnesium fluoride. The percent mass of elements of MgF2 are 39.012 of Mg and 60.989 of F.
- Magnesium fluoride is a binary ionic compound. It is comprised of two fluorine and one magnesium atom. Since it is an ionic compound, it is made up of anions and cations.
- Magnesium is metal and has a much lower electronegativity than fluorine. Hence, this compound consists of two fluoride anions and a magnesium cation.
- Mass percent of an element in a compound ⇒
( mass of the elements/ molar mass of compound) × 100
Molar mass of MgF₂, is 62.301g/mol (24.305+2×18.998)
Mass Percent of Mg =( 24.305 / 62.301) × 100
= 39.012%
Mass percent of F = (18.998×2 / 62.301) ×100
= 60.989%
Thus we can conclude as :
Element Atomic Number of Atoms Mass Percent.
mass
Mg 24.305 1 39.012%
F 18.998 2 60.989%
Learn more about mass percent at brainly.com/question/13896694
#SPJ4