The question asks to identify which metal among Sodium, Magnesium, Aluminium, and Calcium has the highest atomic number. The atomic number ($Z$) represents the number of protons in the nucleus of an atom and uniquely identifies a chemical element.
To find the metal with the highest atomic number, let's list the atomic numbers for each element provided:
| Metal | Symbol | Atomic Number ($Z$) |
|---|---|---|
| Sodium | Na | $Z=11$ |
| Magnesium | Mg | $Z=12$ |
| Aluminium | Al | $Z=13$ |
| Calcium | Ca | $Z=20$ |
Now, we compare the atomic numbers listed:
Comparing these values, we can see that 20 is the largest number among 11, 12, 13, and 20.
The atomic number 20 corresponds to the element Calcium.
Therefore, among the given options, Calcium is the metal with the highest atomic number.
The II group elements in the periodic table is known as
The correct order of decreasing electron gain enthalpy with negative sign for chalcogens is - Identify
Modern periodic table has:
‘Triclosan’, considered harmful when exposed to high levels for a long time, is most likely present in which of the following?