Question

The 14 elements collectively placed in group 3 and 7th period are

Answer 1

Answer:

Actinides

Explanation:

7th period and 3rd group elements are known as Actinides.there are 14 elements are there in actinides.

Answer 2

Answer:

The fifteen elements collectively placed in group 3(lllB) and 7th period are called Actinides.

Explanation:

What are Actinides

• Among the actinide series, there are 15 metallic chemical elements ranging from 89 to 103 atomic numbers, actinium to lawrencium.
• From its first element, actinium, the actinide series gets its name.

Common properties of Actinides:

• Actinides have a high electropositivity.
• They tarnish readily in air.
• They are pyrophoric (ignite spontaneously in the air), particularly finely divided powdered form.
• These metals are dense and have distinctive structures.

List of Elements- Actinides

The 15 elements that are part of the Actinides series are as follows:

1. Actinium (Ac)
2. Thorium (Th)
3. Protactinium (Pa)
4. Uranium (U)
5. Neptunium (Np)
6. Plutonium (Pu)
7. Americium (Am)
8. Curium (Cm)
9. Berkelium (Bk)
10. Californium (Cf)
11. Einsteinium (Es)
12. Fermium (Fm)
13. Mendelevium (Md)
14. Nobelium (No)
15. Lawrencium (Lr)