Answer:
Land resources such as gravel and bedrock are used to construct buildings, roads, and sidewalks. Land is also where city structures—such as buildings, roads, and sidewalks—are constructed. People use land resources such as bedrock and aggregate to construct buildings, roads, and sidewalks.
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Answer:
A product in science is a substance that is formed when two or more chemicals react.
Explanation:
When a chemical reaction takes place, a new substance is often created from the atoms or molecules of the original substances. There are often multiple products formed in a reaction.
Heating an atom excites its electrons and they jump to higher energy levels. When the electrons return to lower energy levels, they emit energy in the form of light. ... Every element has a different number of electrons and a different set of energy levels. Thus, each element emits its own set of colours.
Answer:
Option-B (Carbon and Silicon)
Explanation:
Among the given pairs only carbon and silicon have the most similar properties. This is because,
Sodium and Magnesium belong to different groups. Sodium present in Group I has one electron in its valence shell and capable of transferring only one electron while, Magnesium present in Group II have two electrons in its valence shell and is capable of donating two electrons. Hence, both show different properties.
Example:
2 Na + Cl₂ → NaCl
Mg + Cl₂ → MgCl₂
As shown in reactions when Sodium and Magnesium are treated with Cl₂ they give a products with different proportions.
Carbon and Silicon show almost same properties because both belong to Group IV hence both are capable of forming four bonds. Also, they share the same property of self linkage in making a long chains.
Argon and Chlorine also belong to two different groups. Argon is present in Group VIII (Noble Gases) and Chlorine is present in Group VII (Halogens). Hence, Argon is an inert specie which is non reactive while Chlorine gives different reaction easily.
Potassium and Calcium belong to different groups. Potassium present in Group I has one electron in its valence shell and capable of transferring only one electron while, Calcium present in Group II have two electrons in its valence shell and is capable of donating two electrons. Hence, both show different properties.
Example:
2 K + Cl₂ → KCl
Ca + Cl₂ → CaCl₂
As shown in reactions when Potassium and Calcium are treated with Cl₂ they give a products with different proportions.
