Formula mass is used for which of the following substances?
The formula mass of a substance is defined as the sum of the atomic masses of constituent atoms in an ionic compound. This is generally used for ionic compounds which do not contain discrete molecules, but ions as their constituent units.
Chemical Formula for Ionic Compounds:
Which of the following is an element?
Copper is a chemical element with symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity.
Substances whose two or more components completely mix with each other to make a uniform composition are called:
► Homogeneous Mixture: Mixtures having a uniform composition throughout their body.
Example: Mixture of salt and water, a mixture of sugar and water, air, lemonade, soda water, etc.
► A mixture of salt in water is a classic example. This is because here, the boundary, between salt and water can never be differentiated. When a ray of light is passed through the mixture of salt and water, the path of light is not seen.
Which of the following is a compound?
Water is a compound:
Arsenic is a/an:
A pure substance can only be:
Thus, a pure substance can only be an element or a compound.
Which of the following is a characteristic property of both mixtures and compounds?
Mixture and a compound both follow the law of conservation of mass so their weight equals to the sum of mass of their components.
The correct relationship between picometer and nanometer is
The correct answer is Option A.
1 picometer = 10-12 m
1 nanometer=10-9 m
So, 1 picometer = 0.001 nanometer . From this we get 1 nanometer= 1000 picometer.
One sample of air is found to have 0.03% carbon dioxide and another sample 0.02%. This illustrates that:
Air is a mixture. When we combine more than one type of element, known as a mixture. The different percentages are showing that these other elements are present.
Which one of the following is not a mixture?
Distilled water is the pure form of water with no impurities present in it; others are the mixture of two or more components.