A) Ca, Mg, Be
The first ionization energy increases as we move up a group because of the smaller atomic size and less shielding of electrons.
Answer:
they require more testing in real-word conditions
Explanation:
One of the biggest reasons for this very slow uptake of hydrogen vehicles is the existing infrastructure. ... The sceptics' first argument against hydrogen vehicles is that they're less efficient than EVs are. Because hydrogen doesn't occur naturally, it has to be extracted, then compressed in fuel tanks.
