Which element has the highest density in the periodic table?

1. Which element has the highest density in the periodic table? +

Answer

Osmium (Os) — approximately 22.59 g/cm³

Detailed Explanation

Osmium (Os), atomic number 76, is generally regarded as the densest naturally occurring element.

Density = Mass ÷ Volume
ρ = m / V

Osmium has an extremely high density because it combines a very high atomic mass with a very small atomic volume and efficient crystal packing.

Its density is approximately:

ρ ≈ 22.59 g cm⁻³

It is slightly denser than Iridium (Ir), whose density is about 22.56 g/cm³.

Practical Comparison

Os ~22.59 g/cm³
Highest

Ir ~22.56 g/cm³
Very high

Pt ~21.45 g/cm³
Very high

Au ~19.32 g/cm³
Very high

Why is Osmium so Dense?

The density of an element depends mainly on:

• Atomic mass
• Atomic volume
• Crystal structure and packing efficiency

Osmium has a combination of high atomic mass and very compact atomic packing. Therefore, a large amount of mass is contained in a relatively small volume.

High mass + Small volume → Very high density

Important Exam Point

Highest density element: Osmium (Os)
Atomic number: 76
Block: d-block
Series: 5d transition series
Density: ≈ 22.59 g/cm³

Remember: Density is different from atomic mass. The element with the highest atomic mass is not automatically the element with the highest density.

30 Related MCQs with Solutions

1. Which element has the highest density in the periodic table?

A. Gold

B. Platinum

C. Osmium

D. Mercury

Answer: C. Osmium (Os)
Osmium has a density of approximately 22.59 g/cm³.

2. The atomic number of Osmium is:

A. 74

B. 75

C. 76

D. 77

Answer: C. 76

3. Osmium belongs to which block?

A. s-block

B. p-block

C. d-block

D. f-block

Answer: C. d-block

4. Osmium belongs to which series?

A. 3d series

B. 4d series

C. 5d series

D. 4f series

Answer: C. 5d series

5. Density is defined as:

A. Volume/Mass

B. Mass/Volume

C. Mass × Volume

D. Mass + Volume

Answer: B. Mass/Volume

6. The approximate density of Osmium is:

A. 10.5 g/cm³

B. 19.3 g/cm³

C. 22.59 g/cm³

D. 25.0 g/cm³

Answer: C. 22.59 g/cm³

7. Which element has a density very close to Osmium?

A. Iridium

B. Sodium

C. Potassium

D. Aluminium

Answer: A. Iridium

8. Which of the following is denser?

A. Osmium

B. Gold

C. Both have exactly the same density

D. Sodium

Answer: A. Osmium

9. Gold has an approximate density of:

A. 5.0 g/cm³

B. 10.0 g/cm³

C. 19.32 g/cm³

D. 30 g/cm³

Answer: C. 19.32 g/cm³

10. Which factor directly increases density if volume remains constant?

A. Decrease in mass

B. Increase in mass

C. Increase in volume

D. Zero mass

Answer: B. Increase in mass

11. Which of the following is a very dense transition metal?

A. Osmium

B. Lithium

C. Calcium

D. Magnesium

Answer: A. Osmium

12. Which element is generally considered the second-densest naturally occurring element?

A. Iridium

B. Lead

C. Mercury

D. Gold

Answer: A. Iridium

13. Which element has density greater than gold?

A. Osmium

B. Sodium

C. Potassium

D. Calcium

Answer: A. Osmium

14. Which of the following has a density close to 22.5 g/cm³?

A. Osmium

B. Iron

C. Copper

D. Aluminium

Answer: A. Osmium

15. The density of an element depends primarily on:

A. Mass and volume

B. Atomic number only

C. Colour only

D. Melting point only

Answer: A. Mass and volume

16. Which element is liquid at room temperature and has relatively high density?

A. Mercury

B. Sodium

C. Potassium

D. Lithium

Answer: A. Mercury

17. Which element has a density of approximately 21.45 g/cm³?

A. Platinum

B. Iron

C. Copper

D. Zinc

Answer: A. Platinum

18. Osmium is located in which period?

A. 4

B. 5

C. 6

D. 7

Answer: C. Period 6

19. Osmium belongs to which group?

A. Group 6

B. Group 7

C. Group 8

D. Group 9

Answer: C. Group 8

20. The symbol of Osmium is:

A. O

B. Os

C. Om

D. Oe

Answer: B. Os

21. Which of the following is less dense than Osmium?

A. Iridium

B. All listed choices if their densities are below 22.59 g/cm³

C. None

D. Only tungsten

Answer: B
Iridium, gold, platinum and tungsten all have densities below approximately 22.59 g/cm³.

22. Which statement about density is correct?

A. Density = volume/mass

B. Density = mass/volume

C. Density = mass + volume

D. Density = mass × volume

Answer: B. Density = mass/volume

23. Which metal is famous for extremely high density and high melting point?

A. Osmium

B. Sodium

C. Potassium

D. Lithium

Answer: A. Osmium

24. If the volume of a sample is doubled while its mass remains constant, its density becomes:

A. Double

B. Half

C. Four times

D. Unchanged

Answer: B. Half
Since ρ = m/V, doubling V halves the density.

25. Which element is commonly associated with the highest density among naturally occurring elements?

A. Os

B. Fe

C. Al

D. Mg

Answer: A. Os

26. Which of the following has greater density?

A. Aluminium

B. Iron

C. Osmium

D. Sodium

Answer: C. Osmium

27. Osmium is best classified as:

A. Alkali metal

B. Alkaline earth metal

C. Transition metal

D. Noble gas

Answer: C. Transition metal

28. Which pair consists of two very high-density transition metals?

A. Os and Ir

B. Na and K

C. Li and Mg

D. Ca and Ba

Answer: A. Os and Ir

29. Which statement is correct about Osmium?

A. It is a noble gas

B. It is a highly dense transition metal

C. It is an alkali metal

D. It is a halogen

Answer: B. It is a highly dense transition metal

30. Which one is the best answer for the densest naturally occurring element?

A. Gold

B. Lead

C. Osmium

D. Mercury

Answer: C. Osmium

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