Tag: chemistry

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Multiple choice chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

The alkali and alkaline earth metals in groups $I :A$ and $II :A$ are referred to as the light metals because, they have:

  1. low density.

  2. low hardness.

  3. low melting points.

  4. all of the above.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

 The alkali and alkaline earth metals in groups $I :A$ and $II :A$ are referred to as the light metals because they have low density, low hardness, and low melting points.

Multiple choice chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

The most durable metal plating on iron to protect against corrosion is :

  1. Tin plating

  2. Zinc plating

  3. Copper plating

  4. Nickel plating
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Galvanisation is the process of applying a protective zinc coating to iron or steel, to prevent rusting. The most common method is hot dip galvanizing, in which steel sections are submerged in a bath of molten zinc. Hence, zinc plating is the most durable metal plating on iron to protect against corrosion.

Multiple choice chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

Based on the information in each choice below, which of the noble gases would have the greatest density for a $1.00\ L$ sample at room temperature and pressure?

  1. Krypton molar mass $83.8 g/mol$, atomic radius $111$ picometers
  2. Argon molar mass $39.9 g/mol$, atomic radius $94$ picometers
  3. Neon molar mass $20.2 g/mol$, atomic radius $70$ picometers
  4. Helium molar mass $4.0 g/mol$, atomic radius $50$ picometers
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Ans : A Krypton molar mass $83.3\ g/ mol$, atomic radius III picometers.

Note: [ As we go top to bottom, Atomic mass increases. This is because the $e^{\ominus}$ in bigger noble gases are located away from the nucleus and held less tightly by the atom. Therefore the density of krypton is more then $He, Ne$ and $Ar$].

Multiple choice chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

Which of the following physical property of beryllium makes it perfect aerospace material?

  1. High thermal conductivity

  2. Low density
  3. Both $A$ and $B$

  4. Beryllium is not suitable for aerospace mateerial
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

It should be light to make aerospace material. Beryllium has low density and also has high thermal conductivity.

Multiple choice chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

Which of the following metal is famous with magicians for its melting properties?

  1. Tellurium

  2. Gallium

  3. Dysprosium

  4. Rhodium
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Gallium is a metal with lowest melting point. When we hold it and apply pressure with fingers, It melts at room temperature because of low melting point so, it is used by magicians.

Multiple choice chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

Non-metals don't show malleability because of:

  1. lesser extent of bonding than metals.

  2. low density

  3. smaller atomic size

  4. none
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The basic difference between metals and non-metals is the extent of bonding.Metals have very high extent of bonding than that in non-metals which makes the metal malleable.