Answer:
The mass number is defined as the total number of protons and neutrons in an atom. The number of neutrons = mass number − atomic number.
Heat is a form of energy. if the system absorbs heat/ energy it is endo thermic if it releases heat or energy it is eothermic
Answer:
Reshape the hills with terraces
Explanation:
It is the best way of preventing water eroding when it comes of doing agriculture on hills
Explanation:
Let relative ratio of one isotope (62.94 u) be X
Then, relative ratio of other isotope (64.93) will be (1 - X)
Now,
(62.94)x + (64.93)(1 - x) = 63.55
1.99x = 1.38
X = 0.69
<u>Relative Abundance</u> :
(62.94 u) isotope = 69 %
(64.93 u) isotope = 31 %