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egoroff_w [7]
3 years ago
6

What is first and second element of the periodic table?

Chemistry
2 answers:
stira [4]3 years ago
7 0
The elements on the periodic table are listed in increasing atomic number. 

Hydrogen is the first element, and has an A.N. of 1. Also, its very interesting how it doesn't need 8 valence electrons to be stable. 

The second element is Helium, which has an A.N (atomic number) of two. 
WINSTONCH [101]3 years ago
6 0

Hydrogen= First element,H

Helium=Second Element,He


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What are the coefficients of the balanced reaction? _CH4 + _CI2 ➡ _CCI4 + _HCI​
stealth61 [152]

Answer:

CH4 + 4Cl2 --> CCl4 + 4HCl

Explanation: Message me if you need a thorough explanation

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3 years ago
If a proton and an electron are released when they are 5.50×10−10 mm apart (typical atomic distances), find the initial accelera
Vlada [557]

Answer: The initial acceleration of the proton = (4.56 × 10^23) m/s2

The initial acceleration of the electron = (8.36 × 10^26) m/s2

Explanation: The force of attraction between the proton and electron can be computed using the statements of Coulomb's law which state that the force of attraction between two charged particles is directly proportional to the product of the two charges and inversely proportional to the square of their distances apart.

F = (Kq1q2)/(r^2) where K = (9 × (10^9) Nm(C^-2))

But q1 is the charge on a proton = (1.6 × (10^-19)) C

q2 is charge on an electron = -(1.6 × (10^-19)) C

r = (5.50 × (10^-10))mm = (5.50 × (10^-13))m

Computing all that, F = 0.0007616529 N = (7.62 × 10^-4) N

But the force of attraction is converted to that required for motion when they're released.

F = ma.

For proton, m = (1.67 × 10^-27) kg

a = F/m = 0.000762/(1.67 × 10^-27) = (4.56 × 10^23) m/s2

For electron, m = (9.11 × 10^-31) kg

a = F/m = 0.000762/(9.11 × 10^-31) = (8.36 × 10^26) m/s2

QED!

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One of the waste products produced by kidneys is creatinine. A healthy range ofcreatinine in human blood is between 0.50 mg/dL a
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The normal range of creatinine in human blood is between 0.50 mg/dL and 1.1 mg/dL. The patient's blood has a concentration of 0.0082 g/L. Let's convert that value into mg/dL.

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0.0082 g/L = 0.82 mg/dL

0.50 mg/dL < 0.82 mg/dL < 1.1 mg/dL

Answer: The concentration of creatinine = 0.82 mg/dL. It is in the normal range.

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