Different elements produce different colors of light when heated because the electrons in these elements have different permissible energy levels. When an element is heated, the electrons inside it become excited and move to an higher energy level from the ground state. When the electrons drop from this higher energy level, they typically emit energy quantum, the color of the light that is observed at this stage depends on difference that exist in the two energy levels.<span />
Answer: Matter
Explanation:
Matter is anything that has volume and/or mass.
Answer:- The natural abundance of 
is 0.478 or 47.8% and 
is 0.522 or 52.2% .
Solution:- Average atomic mass of an element is calculated from the atomic masses of it's isotopes and their abundances using the formula:
Average atomic mass = mass of first isotope(abundance) + mass of second isotope(abundance)
We have been given with atomic masses for and as 150.919860 and 152.921243 amu, respectively. Average atomic mass of Eu is 151.964 amu.
Sum of natural abundances of isotopes of an element is always 1. If we assume the abundance of as n then the abundance of would be 1-n .
Let's plug in the values in the formula:
151.964=150.919860n+152.921243-152.921243n
on keeping similar terms on same side:
negative sign is on both sides so it is canceled:
The abundance of is 0.478 which is 47.8%.
The abundance of is = 
= 0.522 which is 52.2%
Hence, the natural abundance of is 0.478 or 47.8% and is 0.522 or 52.2% .
Answer:
Mechanical weathering
A. does not change rock composition
C. abrasion
F. ice wedging
Chemical weathering
B. oxidabon
D. changes rock composition
E. acid rain
Explanation:
Answer:
V₂ = 4.7 L
Explanation:
Given data:
Initial volume = 5.0 L
Initial pressure = 1.50 atm
Final pressure = 1240 mmHg (1240/760 = 1.6 atm)
Final volume = ?
Solution:
P₁V₁ = P₂V₂
V₂ = P₁V₁ / P₂
V₂ = 1.50 atm ×5.0 L/1.6 atm
V₂ = 7.5 atm. L /1.6 atm
V₂ = 4.7 L
