Answer: C
Explanation: Pesticides protect our crops, but some studies show that they cause consumers to gain weight:)
<u>Answer:</u> The correct answer is geographical map.
<u>Explanation:</u>
Model is defined as the three dimensional representation of a proposed structure in a smaller scale.
For the given options:
<u>Option 1:</u> PV = nRT
This is a proposed law. This law is known as ideal gas law. A law is defined as the rule which defined a correct procedure. For any gas behaving ideally, this law is used.
<u>Option 2:</u> Geographical map
Map is defined as the diagrammatic representation of an area of land or sea which also shows physical features, roads, cities etc..
A 3-D model can be prepared for geographical map.
<u>Option 3:</u> I believe that aliens exist
This is a hypothetical statement. It is a smart guess by the means of set of assumptions and observations. For its validation, we need to conduct some experiments.
Hence, the correct answer is geographical map.
Atomic mass Sodium ( Na ) = 22.98 u.m.a
22.98 g ----------------- 6.02x10²³ atoms
175 g ------------------- ?? atoms
175 x ( 6.02x10²³) / 22.98 =
4.58x10²⁴ atoms of Na
hope this helps!
Answer: Option (d) is the correct answer.
Explanation:
Metals are the species which contain more number of electrons.
When a specie loses electrons then it acquires a positive charge. Whereas when an atom gains electrons then it acquires a negative charge.
Thus, as metals have more number of electrons, therefore, in order to gain stability metals readily lose electrons.
Hence, metals naturally form positive ions, by losing electrons to empty the valence shell.
Answer:
1 = oxidation
2 = reduction
Explanation:
Oxidation:
Oxidation involve the removal of electrons and oxidation state of atom of an element is increased.
2I- ----> I₂+ 2e⁻
Reduction:
Reduction involve the gain of electron and oxidation number is decreased.
F + e⁻ ----> F⁻
Consider the following reactions.
4KI + 2CuCl₂ → 2CuI + I₂ + 4KCl
the oxidation state of copper is changed from +2 to +1 so copper get reduced.
CO + H₂O → CO₂ + H₂
the oxidation state of carbon is +2 on reactant side and on product side it becomes +4 so carbon get oxidized.
Na₂CO₃ + H₃PO₄ → Na₂HPO₄ + CO₂ + H₂O
The oxidation state of carbon on reactant side is +4. while on product side is also +4 so it neither oxidized nor reduced.
H₂S + 2NaOH → Na₂S + 2H₂O
The oxidation sate of sulfur is -2 on reactant side and in product side it is also -2 so it neither oxidized nor reduced.
