The number of electrons in a completely filled second shell of an atom will be 8.
The basic number of ordinary components that make up a chemical element is just an atom.
As per Bohr's atomic model, electrons orbit or shell surrounding the nucleus in a precise circular path.
It is known that by the electronic configuration atoms posses 2,8,18,32.
Hence, there are 8 electron will be found in second shell of the atom.
The number of electrons in a completely filled second shell of an atom will be 8.
To know more about shell and atom.
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Volume: ? L
Answer:
Hygroscopic substances
Explanation:
Hygroscopic compounds are those that absorb moisture and a large amount of water and they become wet. They should not be confused with deliquescent substances that absorb water and forms solution.
Hygroscopic substances froms pasty substances and not solution while the liquid ones only becomes diluted. Examples are sodium trioxonitrate(v) (NaNO₃), copper (ii) oxide CuO, and concentrated tetraoxosulphate (vi) acid (H₂SO₄)
Hydrophilic substances, like cellulose found in cotton and paper pulp, can soak up large amounts of water. Some chemical compounds, such as sodiumcarbonate decahydrate and copper(II) sulfate pentahydrate, have this property. Moreover, phosphorus(V) oxide, although used for removing water from compounds, also shows a great affinity for water.
A compound that has the ability to soak up large amounts of water is termed a hydrophilic substance. Hydrophilic substances are attracted to water, absorbing it readily. For example, cotton and paper pulp, used in towels, are made of molecules of cellulose that contain many –OH groups.
Water molecules are attracted to these -OH groups and form hydrogen bonds with them, drawing large amounts of H₂O up the cellulose fibers. Additionally, some compounds like sodium carbonate decahydrate and copper(II) sulfate pentahydrate also have the ability to soak up water. Another example is phosphorus(V) oxide, which has a great affinity for water and is used for removing water from compounds.
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A.
Only the Fe is unbalanced.
B.
Only the O is unbalanced
C.
Fe and O are both unbalanced.
D.
C and O are both unbalanced
These are two questions and two answers.
Question 1: Law of Conservation of Mass
Answer: option B. The total mass remains the same during a chemical reaction.
Explanation:
The law of conservation of mass is a universal law. It states that mass is mass is neither created or destroyed, but is is conserved.
In chemical reactions, that means that, always, the total mass of the reactants equals the total mass of the products or, as the option B. states, during a chemical reaction the total mass remains the same.
Since, in chemical reactions, the atoms are not modified (the atoms just bond in different form or with different atoms), that implies that total number of each kind of atoms in the reactants equals the total number of the same kind of atoms in the products.
That is the basis for balancing the chemical equations and for the stoicheometric calculations.
Question 2 . Which element(s) are not balanced in this equation?
Answer: option A. Only the Fe is unbalanced.
Explanation:
1) Given equation: Fe₂O₃ + 3 CO → Fe + 3 CO₂
2) Count the number of atoms of each kind on each side of the equation
i) Fe
reactant side: 2
product side: 1
Therefore, Fe is not balanced
ii) O
reactant side: 3 + 3 = 6
Product side: 3 × 2 = 6
Therefore, it is balanced
iii) C
reactant side: 3
product side: 3
Therefore, C is balanced.
3) Conclusion: Only the Fe is unbalanced.
For #1, the answer is B. The total mass remains the same during a chemical reaction.
For #2, given Fe2O3 + 3CO -> Fe + 3CO2
Fe is unbalanced, and O is also unbalanced
Therefore, Option C: Fe and O are both unbalanced, is true.
by adding valence electrons
by adding or removing protons
by adding or removing neutrons
Answer: by adding or removing neutrons
Explanation: