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3 years ago

5

Please help Sodium (Na) has an atomic number of 11 and an atomic mass of 23. Which of the following correctly shows the electron

arrangement for sodium?
2, 9 2, 8, 1 2, 8, 2 2, 9, 1

1 answer:

fredd [130]3 years ago

3 0

2,8,1
It's in group 1, so its outershell only has 1 electron, and the other shells are completely filled, so 2 then 8. :)

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PLEASE HELP WITH ALL

Gala2k [10]

Answer:

Question 1: D

Question 2: B C E F

Question 3: A

Question 4: A

Question 5: A

5 0

4 years ago

Read 2 more answers

2567 milliliters to liters

andrew-mc [135]

Answer:

2.567 litres

Explanation:

I dont have a proper explanation sorry

6 0

3 years ago

A certain man needed 400N of force to pull a load through a distance of 150cm in 8s . Calculatell i) the work done by man ii) th

Igoryamba

Answer:

a) 600 J

b) 75 W

Explanation:

Force= 400 N, distance = 150 cm = 1.5 m, time= 8s

a) Work is the product of force acting on an object and distance (or displacement). The S.I unit of work is the joules.

Work = force × distance = 400 × 1.5 = 600 J

b) Power is the amount of energy transferred per unit time. It is the ratio of work to time. The S.I unit of power is watt

Power = work/time = 600 / 8 = 75 W

5 0

3 years ago

Assume that a point mutation changes the codon AUU to AUC. Why is this a neutral mutation

lukranit [14]

I used the genetic code table. mRNA codon ===> amino acid

1st base 2nd base 3rd base
A U U ===> Isoleucine
A U C ===> Isoleucine

The point mutation of codon AUU to AUC is a neutral mutation because it neither benefits nor deter the ability of the organism to survive and reproduce.

As you can see, Both codons result to the Isoleucine amino acid.

Another codon that will still result to the Isoleucin amino acid is AUA.

3 0

3 years ago

In this experiment we will be using a 0.05 M solution of HCl to determine the concentration of hydroxide (OH-) in a saturated so

gulaghasi [49]

<u>Answer:</u> The moles of hydroxide ions present in the sample is 0.0008 moles

<u>Explanation:</u>

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is HCl.

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is $Ca(OH)_2$

We are given:

$n_1=1\\M_1=0.05M\\V_1=16mL\\n_2=2\\M_2=?M\\V_2=36.0mL$

Putting values in above equation, we get:

$1\times 0.05\times 16=2\times M_2\times 36\\\\M_2=\frac{1\times 0.05\times 16}{2\times 36}=0.011M$

To calculate the moles of hydroxide ions, we use the equation used to calculate the molarity of solution:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution (in mL)}}$

Molarity of solution = 0.011 M

Volume of solution = 36.0 mL

Putting values in above equation, we get:

$0.011=\frac{\text{Moles of }Ca(OH)_2\times 1000}{36}\\\\\text{Moles of }Ca(OH)_2=\frac{0.011\times 36}{1000}=0.0004mol$

1 mole of calcium hydroxide produces 1 mole of calcium ions and 2 moles of hydroxide ions.

Moles of hydroxide ions = (0.0004 × 2) = 0.0008 moles

Hence, the moles of hydroxide ions present in the sample is 0.0008 moles

8 0

3 years ago