They are the outer layer of the electron layers.
Answer:
1)Na2O
let the valency of Na is x
2(x)+(2)=0
2x+2=0
2x=-2
x=-1
2)ZnO
let the valency of Zn is x
x+2=0
x=-2
3)Al2O3
let the valency of Al is x
2(x)+3(2)=0
2x+6=0
2x=-6
x=-3
4)MgO
let the valency of Mg is x
x+2=0
x=-2
The bromide concentration in this solution of calcium bromide dissolved in enough water to give 469.1 mL is 1.75 × 10-⁵M.
<h3>How to calculate concentration?</h3>
The concentration of a solution can be calculated by dividing the number of moles of the substance by its volume.
No of moles of calcium bromide is calculated as follows:
moles = 1.642 ÷ 199.89 = 8.215 × 10-³moles
Molarity = 8.215 × 10-³moles ÷ 469.1mL = 1.75 × 10-⁵M
Therefore, the bromide concentration in this solution of calcium bromide dissolved in enough water to give 469.1 mL is 1.75 × 10-⁵M.
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Answer:Scientific knowledge can change because it is often examined and re-examined by new investigations and scientific argumentation. Because of these frequent examinations, scientific knowledge becomes stronger, leading to its durability. ... B: Scientific knowledge is durable and robust, but open to change.
<h3>your query : </h3>
Which statement about photosynthesis is FALSE?
Answer:
b. Oxygen is needed as a reactant to produce
glucose is the incorrect statement here
Explanation:
plants uses simple raw materials to prepare their food , which includes water ( H2O ) and Carbon dioxide ( CO2 ).
and traps sunlight by Green pigments known as chlorophyll and stores these energy in bonds of glucose molecules
so ,
after this reaction glucose and oxygen is formed as products
● hence we conclude that Oxygen is not needed as a reactant to produce glucose , oxygen is the bi product formed during photosynthesis.