What is the total number of electrons in the valence shell of an atom of aluminum in the ground state?(1) 8 (3) 3
(2) 2 (4) 10
Answers
Answer:
C. 3
Explanation:
If you look at aluminum (Al) in the Periodic Table of the Elements, you will see that its electron configuration is 2-8-3. The last number indicates the valence shell, which contains three electrons.
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Corrosion is what type of chemical change? a. oxidation b. phase change c. physical change d. combustive reaction
What is the dog's momentum
Explain how the system of the flask and the balloon illustrates the conservation of mass.
The Kw of water varies with temperature. Calculate the pH of water at 46⁰C with a Kw = 1.219 x 10-14. Show all calculations leading to an answer.
Answers
2 NaOH (s) + CO₂ (g) → Na₂CO₃ (s) + H₂O (l)
Explanation:
The most probably chemical reaction is:
2 NaOH (s) + CO₂ (g) → Na₂CO₃ (s) + H₂O (l)
Sodium Hydroxide (solid) + Carbon Dioxide (gas) → Sodium Carbonate (solid) + Water (gas)
In this reaction the water you obtain have to be in liquid form because the reaction takes place at room temperature. However because the student left the beaker for 24 hours, the water have a plenty of time to evaporate, so in the end only sodium carbonate (Na₂CO₃) remained in the beaker.
number of moles = mass / molar weight
number of moles of NaOH = 0.4 / 40 = 0.01 moles
Taking in account the chemical reaction, we devise the following reasoning:
if 2 moles of NaOH produce 1 mole of Na₂CO₃
then 0.01 moles of NaOH produce X mole of Na₂CO₃
X = (0.01 × 1) / 2 = 0.005 moles of Na₂CO₃
mass = number of moles × molar weight
mass of Na₂CO₃ = 0.005 × 106 = 0.53 g
mass of Na₂CO₃ = mass of beaker and its contents after 24h - mass of empty beaker
mass of Na₂CO₃ = 113.09 - 112.58 = 0.51 g which is close the theoretical value of 0.53 g.
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number of moles
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(2) an OH- ion (4) an electron
Answers
Answer : The correct option is, (1) an ion
Explanation :
According to the Bronsted-Lowry or acid-base concept, a substance is called as an acid if it can donate a proton and a substance is called as a base if it can accept a proton. And the substance may be a molecule or an ion.
When a water molecule acts as an acid then it can donate a proton or ion.
When a water molecule acts as a base then it can accepts a proton or ion.
Hence, the correct option is, (1) an ion
Final answer:
In accordance to the Brønsted-Lowry theory, a water molecule acts as a base when it accepts an H+ ion during the ionization of water. This capability for water to function both as an acid when donating an H+ ion, and a base when accepting an H+ ion makes it amphoteric.
Explanation:
According to the Brønsted-Lowry theory of acids and bases in Chemistry, a water molecule acts as a base when it accepts an H+ ion. This occurs during the ionization of water, a chemical reaction that takes place when water auto-ionizes into a hydronium ion (H3O+) and a hydroxide ion (OH-). Therefore, the correct choice from your options is (1) an H+ ion.
Water acts as an acid when it donates an H+ ion and as a base when it accepts an H+ ion, transforming it into a hydronium ion. This capacity for water to act as both an acid and a base makes it amphoteric.
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4 faces
6 faces
8 faces
Answers
The tetragonal crystal system below possesses two faces. The two axes are of equal length and are in the same plane, the main axis is either longer or shorter and all three intersect at right angles. The Crystal shapes include four-sided prisms and pyramids, hexacisochedron.
Answers
Answers
2) Lithium
3) Phosphorus
Answers
Answer:
A.
Explanation:
The amount of mass always stays the same, matter cannot be created nor destroyed, it can only change forms. Thus, the answer is A.
In a chemical reaction the total mass of all the substances taking part in the reaction remains the same. Also, the number of atoms in a reaction remains the same. Mass cannot be created or destroyed in a chemical reaction.
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