Answer:
The reflection of sound waves
Explanation:
An echo is a reflection of sound that bounces of of one thing to another.
A.atomic mass(a)=16
atomic mass(b)=18
b.a and b are isotopes
c.(a)=2,6
(b)=2,6
Answer:
moving across te periodic table electronegativity increases.
Explanation:
as we move across a period the effective nuclear charge increases as the number of protons in nucleus increases. due to increase in effective nuclear charge electronegativity increases
Your answer is C
amino acids are created by a bond of two carbon atoms and each carbon is part of a different group, one negative and one positive. when the chemical reactions occurs, it creates the several diff amino acids