Seven
Elements do not contain more than 7 electron shells.
Question is incomplete. Complete question is attached below
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Answer: Option A: HCO3-(aq.)
Reason:
From the reaction, it can be seen that following reaction occurs in forward direct
HCO3-(aq) + H2O(l) → H2CO3(aq) + OH-(aq)
In above forward reaction, HCO3- accepts proton from H2O to generate H2CO3. Thus, according to Lowry and Bronsted theory of acid-base,
HCO3- is a base, while
H2CO3 is a conjugate acid.
Answer:
23.0733 L
Explanation:
The mass of hydrogen peroxide present in 125 g of 50% of hydrogen peroxide solution:

Mass = 62.5 g
Molar mass of
= 34 g/mol
The formula for the calculation of moles is shown below:
Thus, moles are:

Consider the given reaction as:

2 moles of hydrogen peroxide decomposes to give 1 mole of oxygen gas.
Also,
1 mole of hydrogen peroxide decomposes to give 1/2 mole of oxygen gas.
So,
1.8382 moles of hydrogen peroxide decomposes to give ![\frac {1}{2}\times 1.8382 mole of oxygen gas. Moles of oxygen gas produced = 0.9191 molGiven: Pressure = 746 torr The conversion of P(torr) to P(atm) is shown below: [tex]P(torr)=\frac {1}{760}\times P(atm)](https://tex.z-dn.net/?f=%5Cfrac%20%7B1%7D%7B2%7D%5Ctimes%201.8382%20mole%20of%20oxygen%20gas.%20%3C%2Fp%3E%3Cp%3EMoles%20of%20oxygen%20gas%20produced%20%3D%200.9191%20mol%3C%2Fp%3E%3Cp%3EGiven%3A%20%3C%2Fp%3E%3Cp%3EPressure%20%3D%20746%20torr%0A%3C%2Fp%3E%3Cp%3EThe%20conversion%20of%20P%28torr%29%20to%20P%28atm%29%20is%20shown%20below%3A%0A%3C%2Fp%3E%3Cp%3E%5Btex%5DP%28torr%29%3D%5Cfrac%20%7B1%7D%7B760%7D%5Ctimes%20P%28atm%29)
So,
Pressure = 746 / 760 atm = 0.9816 atm
Temperature = 27 °C
The conversion of T( °C) to T(K) is shown below:
T(K) = T( °C) + 273.15
So,
T₁ = (27 + 273.15) K = 300.15 K
Using ideal gas equation as:
PV=nRT
where,
P is the pressure
V is the volume
n is the number of moles
T is the temperature
R is Gas constant having value = 0.0821 L.atm/K.mol
Applying the equation as:
0.9816 atm × V = 0.9191 mol × 0.0821 L.atm/K.mol × 300.15 K
<u>⇒V = 23.0733 L</u>
Answer:
See the images below
Step-by-step explanation:
To draw a dot diagram of an atom, you locate the element in the Periodic Table and figure out how many valence electrons it has. Then you distribute the electrons as dots around the atom,
a. Silicon.
Si is in Group 14, so it has four valence electrons.
b. Xenon
Xenon is in Group 18, so it has eight valence electrons. We group them as four pairs around the xenon atom.
c. Calcium
Calcium is in Group 2, so it has two valence electrons. They are in a single subshell, so we write them as a pair on the calcium atom.
d. Water
Oxygen is in Group 16, so it has six valence electrons. The hydrogen atoms each contribute one electron, so there are eight valence electrons.
Chemists often use a dash to represent a pair of electrons in a bond.
Answer:
This atomic model has changed over time. Scientists used the model to make predictions. Sometimes the results of their experiments were a surprise and they did not fit with the existing model. Scientists changed the model so that it could explain the new evidence.
Explanation: