Answer:
I think the answer should be B. Number of valence electrons
Explanation:
Matter also exhibits physical properties. Physical properties are used to observe and describe matter. Physical properties can be observed or measured without changing the composition of matter. These are properties such as mass, weight, volume, and density.
Answer:
The second one is the correct statement.
Explanation:
An atom consists of a dense, heavy, positively charged central part called nucleus. It consists of neutrons and protons.
The electrons revolves around the nucleus in circular paths. These electrons are called planetary electrons because they can be compared to various planets revolving around the sun and the nucleus is compared with sun.
Answer:
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Explanation:
The order of boiling point depends upon the type of interactions present between the molecules.
Potassium fluoride (KF) is an ionic compound and the opposite ions are held together by strong electrostatic forces.
is a covalent compound and the molecules are held together by weak van der Waals' forces.
Formaldehyde is a polar compound due to presence of polar carbonyl group. Hence dipole-dipole force is present between formaldehyde molecules.
Thus the decreasing order of boiling point is:
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