Lewis structure cannot show the numbers of valences
1.65g MgO = 1g Mg
1.65 - 1 = 0.65 g of O in MgO
solve it using proportion:
1g Mg / 0.65g O = x (g) Mg / 16g O
or 1 / 0.65 = x / 16
24.6 g is the answer.
if 1 gram of oxygen requires 1.65 grams of Mg
then 16 grams of oxygen will require 16 ( 1.65) or 26.4 grams.
1) T
2) F- the heart pumps blood
3) T
4) F- atria and ventricles
5) T
6) T
7) T
8) T
9) F- your heart rate goes down but doesn't stop
10) T
1) D
2) B
3) A
4) E
5)C
Answer: During the summer, the sun's rays hit the Earth at a steep angle. ... Also, the long daylight hours allow the Earth plenty of time to reach warm temperatures. During the winter, the sun's rays hit the Earth at a shallow angle. These rays are more spread out, which minimizes the amount of energy that hits any given spot.
Answer:
1.55×10²² molecules.
Explanation:
We'll begin by calculating the number of mole in 5.32 g of pure lead (Pb). This can be obtained as follow:
Mass of Pb = 5.32 g
Molar mass of Pb = 207 g/mol
Mole of Pb =?
Mole = mass /molar mass
Mole of Pb = 5.32/207
Mole of Pb = 0.0257 mole
Finally, we shall determine the number of molecules in 0.0257 mole of Pb. This can be obtained as follow:
From Avogadro's hypothesis,
I mole of Pb contains 6.02×10²³ molecules.
Therefore, 0.0257 mole will contain = 0.0257 × 6.02×10²³ = 1.55×10²² molecules.
Therefore, 5.32 g of pure lead (Pb) contains 1.55×10²² molecules.
