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kati45 [8]
3 years ago
11

Which element has 5 energy levels and 2 valence electrons?

Chemistry
1 answer:
ratelena [41]3 years ago
5 0

Answer:

Element 38: Strontium

Explanation:

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So I am lost and I don't know how what any of those conversion factor things are and I'm wondering how to do #2,3, and 4. (I did
dalvyx [7]

Explanation:

#2.

A centigram is 1/100 of a gram, so that means a gram equals 100 centigrams.

Therefore you multiply 72.4 grams by 100/1 (or just 100), and get 7240 cg.

You did that one right but put the wrong unit in the answer. It is is cg ( centigrams).

#3.

1 liter is equal to 1000 milliliters, and I kiloliter is equal to 1000 liters. So one kiloliter is 1000*1000 milliliters or 1,000,000 milliliters.

The conversion factor would be

1/1000000

#4.

1 gigabyte is equal to 10^9 bytes.

I byte is equal to 10^9 bytes.

So 1 gigabyte is 10^9 * 10^9 nanobytes, or 10^18.

The conversion factor would be (1*10^18)/1.

6 0
3 years ago
Rocks and sand are nonliving .all organisms are
solong [7]
Hey there!

Rocks and sand are nonliving. All organisms are living.
Living organisms have five characteristics. Living organisms respond to a stimulus, need energy, grow, reproduce, and get rid of wastes. All living organisms consist of cells. 

Hope this helps! Have a Brainly day! :D
5 0
3 years ago
The frequency factors for these two reactions are very close to each other in value. Assuming that they are the same, compute th
MrRissso [65]

The question is incomplete, complete question is :

The frequency factors for these two reactions are very close to each other in value. Assuming that they are the same, compute the ratio of the reaction rate constants for these two reactions at 25°C.

\frac{K_1}{K_2}=?

Activation energy of the reaction 1 ,Ea_1 = 14.0 kJ/mol

Activation energy of the reaction 2,Ea_1  = 11.9 kJ/mol

Answer:

0.4284 is the ratio of the rate constants.

Explanation:

According to the Arrhenius equation,

K=A\times e^{\frac{-Ea}{RT}}

The expression used with catalyst and without catalyst is,

\frac{K_2}{K_1}=\frac{A\times e^{\frac{-Ea_2}{RT}}}{A\times e^{\frac{-Ea_1}{RT}}}

\frac{K_2}{K_1}=e^{\frac{Ea_1-Ea_2}{RT}}

where,

K_2 = rate constant reaction -1

K_1 = rate constant reaction -2

Activation energy of the reaction 1 ,Ea_1 = 14.0 kJ/mol = 14,000 J

Activation energy of the reaction 2,Ea_1  = 11.9 kJ/mol = 11,900 J

R = gas constant = 8.314 J/ mol K

T = temperature = 25^oC=273+25=298 K

Now put all the given values in this formula, we get

\frac{K_1}{K_2}=e^{\frac{11,900- 14,000Jl}{8.314 J/mol K\times 298 K}}=2.3340

0.4284 is the ratio of the rate constants.

7 0
3 years ago
You can practice converting between the mass of a solution and mass of solute when the mass percent concentration of a solution
vfiekz [6]

Answer:

450. g of 0.173 % KCN solution contains 779 mg of KCN.

Explanation:

Mass of the solution = m

Mass of the KCN in solution = 779 mg

Mass by mass percentage of KCN solution = 0.173%

(m/m)\%=\frac{\text{Mass of solute}}{\text{Mass of solution}}\times 100

0.173\%=\frac{779 mg}{m}\times 100

m=\frac{779 mg}{0.173}\times 100= 450,289 mg

1 mg = 0.001 g

m = 450,289 mg × 0.001 g = 450.289 mg ≈ 450. g

450. g of 0.173 % KCN solution contains 779 mg of KCN.

6 0
3 years ago
What is the H+ concentration when pH is 2, 6, 7, 8, and 12?
Mariulka [41]

Answer:

See below.

Explanation:

pH = - log (H+)

So the pH of 1 x 10^-7 M solution is 7.

I'm sorry but I'm not sure about what the other units mean, so Im not sure of the answer to those.

If you convert the other units to the form  1 x 10^-n  then the pH will be n.

6 0
3 years ago
Read 2 more answers
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