For sig figs, you count the total number of numbers that aren’t 0, you only count 0 if they are after a decimal point. since there is not a decimal point, there are 2 significant figures, answer A
Answer:
D =Average atomic mass = 10.801 amu.
5) True
Explanation:
Abundance of B¹⁰= 19.9%
Abundance of B¹¹ = 80.1%
Atomic mass of B¹⁰ = 10 amu
Atomic mass of B¹¹ = 11 amu
Average atomic mass = ?
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (10×19.9)+(11×80.1) /100
Average atomic mass = 199 + 881.1 / 100
Average atomic mass = 1080.1 / 100
Average atomic mass = 10.801 amu.
2)A chemical reaction is one in which a new elements is created
True
False
Answer:
In chemical reaction new substances are created.
For example:
Photosynthesis:
It is the process in which in the presence of sun light and chlorophyll by using carbon dioxide and water plants produce the oxygen and glucose.
Carbon dioxide + water + energy → glucose + oxygen
water is supplied through the roots, carbon dioxide collected through stomata and sun light is capture by chloroplast.
Chemical equation:
6H₂O + 6CO₂ + energy → C₆H₁₂O₆ + 6O₂
it is known from balanced chemical equation that 6 moles of carbon dioxide react with the six moles of water and created one mole of glucose and six mole of oxygen.
Molarity of solution = 1.6 M
<h3>Further explanation</h3>
Given
40 g NaOH
6 L solution
Required
Steps to solve the problem of molarity
Solution
No additional information about the question.
If you want to make the solution above, then we just need to put the existing NaOH (40 g) into 6 L of water, then do the stirring (in a warm temperature above the hot plate will speed up the NaOH dissolving process)
But if you want to know the molarity of a solution, then
- 1. we calculate the moles of NaOH
MW(molecular weight) of NaOH=
Ar Na+ Ar O + Ar H
23 + 16 + 1 = 40 g/mol
so mol NaOH :
Answer:
Read the article on Mine Tools called "Active Listening"
Explanation:
Ive used it before for assignments. Its pretty informative and only takes like 10 minutes to read
