What is the atomic number of Helium according to the modern periodic table?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 2.
- The atomic number of Helium (He) according to the modern periodic table is 2. This means that a helium atom has 2 protons in its nucleus, and it is the second element in the periodic table. Helium is a noble gas and is known for its low reactivity and its use in balloons and cryogenics.
- Helium (symbol He) is a chemical element in the noble gas group (Group 18) of the periodic table. It is the second element in the periodic table, and its atomic number is 2. Helium has the lowest boiling point and melting point of any known substance, with a boiling point of -268.93°C (-452.07°F).