Answer:
The average atomic mass is closer to Si- 28 because this isotope is present in more percentage in the sample.
Explanation:
Given data:
Atomic mass of silicon= ?
Percent abundance of Si-28 = 92.21%
Atomic mass of Si-28 = 27.98 amu
Percent abundance of Si-29 = 4.70%
Atomic mass of Si-29 = 28.98 amu
Percent abundance of Si-30 = 3.09%
Atomic mass of Si-30 = 29.97 amu
Solution:
Average atomic mass = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass)+(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass = (92.21×27.98)+(4.70×28.98)+(3.09×29.97) /100
Average atomic mass = 2580.04 +136.21+92.61 / 100
Average atomic mass = 2808.86 / 100
Average atomic mass = 28.08amu.
The average atomic mass is closer to Si- 28 because this isotope is present in more percentage in the sample.
4. the nervous system uses electrical impulses to send messages through neurons while endocrine glands use hormones to send messages
5. Hormones are released from the endocrine glands
6. a. neck
b. Chest
7. help regulate important functions, such as growth, blood pressure and reproduction; it is small and small and bean shaped.
8. produces hormones that regulate the body's metabolic rate controlling heart, muscle and digestive function, brain development.
9. regulate your metabolism, immune system, blood pressure, respond to stress etc.
10. “enzymes” - break down sugars, fats, and starches
11. cells are unable to use glucose (can’t break down sugar to use as energy)
Oxygen can be obtained from water using electrolysis process as follows:
2 H2O .............> 2H2 + O2
It is given that:
molar mass of water = 10.01 grams and molar mass of O2 = 32 grams
From the balanced chemical equation, we can conclude that:
2 moles of water produce 1 mole of oxygen
2 x 18.01 = 36.02 grams of water produce 32 grams of oxygen.
To calculate how many grams of water must react to produce 50 grams of oxygen, we can use cross multiplication as follows:
mass of required water = 56.28125 grams
Yes, it is possible to go do because it would be 2 stacks of 6
14,200 because all you have to do to solve this is multiply 14.2 kilometers by 1,000 meters to find the distance that he walks.
