Answer: There are 
atoms of hydrogen are present in 40g of urea, 
.
Explanation:
Given: Mass of urea = 40 g
Number of moles is the mass of substance divided by its molar mass.
First, moles of urea (molar mass = 60 g/mol) are calculated as follows.
According to the mole concept, 1 mole of every substance contains 
atoms.
So, the number of atoms present in 0.67 moles are as follows.
In a molecule of urea there are 4 hydrogen atoms. Hence, number of hydrogen atoms present in 40 g of urea is as follows.
Thus, we can conclude that there are atoms of hydrogen are present in 40g of urea, .
Like terms in algebra are terms that have the same variables and power. Constants contain only numbers, we call them constants because their values don't change. Coefficients are the numbers in front of the variable ex: 5y in that expression 5 is the coefficient. So in the expression 2+3a+9a there is one constant which is 2 the likes terms are 3a and 9a because they have the same variable. And the coefficients are 3 and 9 because they are in front of the variable.
Answer:
Carbon
Explanation:
Carbon is the most important element to life. Without this element, life as we know it would not exist. As you will see, carbon is the central element in compounds necessary for life.
