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3 years ago

Help me get this right no links

Chemistry

1 answer:

katrin2010 [14]3 years ago

3 0

Answer:

1 and 2

Explanation:

1. The moon blocks the sun's light from hitting the Earth. (It casts a shadow on the earth by doing so)

2. The moon moves between the Earth and the Sun. (So it blocks the sun's light)

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8. Why would it be a bad idea to make coins made of sodium metal?

Elina [12.6K]

Answer:

Sodium reacts with the oxygen in air. It reacts vigorously with oxygen and the moisture that is already present in the air and thus catches fire.

5 0

3 years ago

Alecsey [184]

Answer:

<h3>no it is not allowed</h3>

Explanation:

<h3>Liwis structure shows the elements symbol with dots thet represents valance electrons ; in second row elements their atomic number is 3 up to 10 , from Li up to Ne from their electron configuration their valance electron will be from 1 up to 8 respectivelly ,if lewis structure represents the element with it is symbol and dots that represents valance electron the second row elements cannot have more than an octet of valance electrons surrounding it.</h3>

<h3>I think it is help ful for you </h3>

3 0

3 years ago

Suppose you are working with a NaOH stock solution but you need a solution with a lower concentration for your experiment. Calcu

Monica [59]

Answer: The volume of the 1.224 M NaOH solution needed is 26.16 mL

Explanation:

In order to prepare the dilute NaOH solution, solvent is added to a given amount of the NaOH stock solution up to a final volume of 250.0 mL.

Since only solvent is added, the amount of the solute, NaOH, in the dilute solution is the same as in the volume taken from the stock solution.

Molarity (M) is calculated from the following equation:

M = n ÷ V

where n is the number of moles of the solute in the solution, and V is the volume of the solution.

Accordingly, the number of moles of the solute is given by

n = M x V

Now, let's designate the stock NaOH solution and the dilute solution as (1) and (2), respectively . The number of moles of NaOH in each of these solutions is:

n (1) = M (1) x V (1)

n (2) = M (2) x V (2)

As the amount of NaOH in the dilute solution is the same as in the volume taken from the stock solution,

n (1) = n (2)

and

M (1) x V (1) = M (2) x V (2)

For the stock solution, M (1) = 1.244 M, and V (1) is the volume needed. For the dilute solution, M (2) = 0,1281 M, and V (2) = 250.0 mL.

The volume of the stock solution needed, V (1), is calculated as follows:

V (1) = M (2) x V (2) ÷ M (1)

V (1) = 0.1281 M x 250.0 mL ÷ 1.224 M

V (1) = 26.16 mL

The volume of the 1.224 M NaOH solution needed is 26.16 mL.

7 0

3 years ago

An isotope of lead can be represented by the following symbol ²⁰⁷ 82 PB. From this symbol, it can be deduced that one atom of th

9966 [12]

Answer:

B) 82 protons

Explanation:

The number of protons for an element never change. 82 Is the atomic number for Pb which is how many protons it has. An isotope means it has more neutrons.

6 0

3 years ago

Question 5 of 5

RUDIKE [14]

Answer:

Tempreture should be the correct answer!!

Explanation:

hope this helps ya!!

8 0

2 years ago