Answer:
Example of a scientific question:
Does the angle of a ramp change the distance a toy car will travel?
Explanation:
441 g CaCO₃ would have to be decomposed to produce 247 g of CaO
<h3>Further explanation</h3>
Reaction
Decomposition of CaCO₃
CaCO₃ ⇒ CaO + CO₂
mass CaO = 247 g
mol of CaO(MW=56 g/mol) :
From equation, mol ratio CaCO₃ : CaO = 1 : 1, so mol CaO :
mass CaCO₃(MW=100 g/mol) :
Explanation:
Elements that belong to same group contains same number of valence electrons. Hence, they tend to show similar chemical properties.
When we move across a period then number of electrons get added to the same shell. As a result, there will be no increase in size of elements.
Also, metals are the elements that belong to group 1, 2 and d-block elements are also known as metals. Metallic character of elements decreases when we move left to right in a periodic table.
As most reactive metals are placed on the left side of periodic table.
Since, size of elements increases on moving down the group. So, an element is able to easily lose its valence electrons because of less force of attraction between its nucleus and valence electrons.
As a result, there will be increase in reactivity of metals on moving down the group.
Thus, we can conclude that given sentences are as follows.
- Elements in the same group have the same number of valence electrons.
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Elements in the same period have the same number of electron shells.
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Metallic elements become less reactive as you move left to right in a period.
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Metallic elements become more reactive as you move top to bottom in a group.
Bioluminescence is a chemical reaction that takes place in a living organism when the organism emits light. Bioluminescence doesn't consume or produce heat, hence it can be neither endothermic nor exothermic reaction. It emits a heatless light not heat.
For bioluminescence, it could be said that it is an exoenergetic reaction because it uses energy from a chemical reaction to produce light.
