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mr_godi [17]
3 years ago
15

What are the elements in the first period

Chemistry
2 answers:
aliina [53]3 years ago
6 0

Answer:

Explanation:

There are only two elements in the first period: hydrogen and helium. We can explain why there is less elements in the first row in modern theories of atomic structure.

Bond [772]3 years ago
6 0

Answer:

"Hydrogen and Helium". Hydrogen and Helium are the elements of the first period in the modern periodic table.

Explanation:

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Part C<br> Number of molecules in 8.437x10-2 mol C6H6
N76 [4]

Answer:

There are 5.08\times 10^{22}\ \text{molecules of}\ C_6H_6  

Explanation:

In this problem, we need to find the number of molecules in 8.437\times 10^{-2} mol of C_6H_6.

The molar mass of C_6H_6 is 6\times 12+1\times 6=78\ g/mol

No of moles = mass/molar mass

We can find mass from above formula.

m=n\times M\\\\m=8.437\times 10^{-2}\ mol\times 78\ g/mol\\\\m=6.58\ g

Also,

No of moles = no of molecules/Avogadro number

N=n\times N_A\\\\N=8.437\times 10^{-2}\times 6.023\times 10^{23}\\\\N=5.08\times 10^{22}\ \text{molecules}

Hence, there are 5.08\times 10^{22}\ \text{molecules of}\ C_6H_6  

5 0
3 years ago
Ammonia, nh3, is a weak base with a kb = 1.8 x 10-5. in a 0.8m solution of ammonia, which has a higher concentration: ammonia (n
insens350 [35]
Answer is: concentration ammonia is higher than concentration of ammonium ion.
Chemical reaction of ammonia in water: NH₃ + H₂O → NH₄⁺ + OH⁻.
Kb(NH₃) = 1,8·10⁻⁵.
c₀(NH₃) = 0,8 mol/L.
c(NH₄⁺) = c(OH⁻) = x.
c(NH₃) = 0,8 mol/L - x.
Kb = c(NH₄⁺) · c(OH⁻) / c(NH₃).
0,000018 = x² /  0,8 mol/L - x.
solve quadratic equation: x = c(NH₄⁺) = 3,79·10⁻³ mol/L.
7 0
3 years ago
Water has a higher specific heat than land. Considering this fact, which state would have the most consistent (unchanged) temper
Darya [45]

Answer:

Florida

Explanation:

Right on edge

8 0
2 years ago
How many molecules of water are there in 1 gram of water​
alisha [4.7K]

Answer:

6.022*1023

Explanation:

3 0
3 years ago
Read 2 more answers
describe covalent and ionic bonding. include how it works, any key terms and how you can identify each bond ( hard, soft, rigid,
Katena32 [7]
A covalent bond is a bond between 2 non metals, they share electrons. Ionic bonding occurs between a metal and a non-metal, and they transfer electrons. 
5 0
3 years ago
Read 2 more answers
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