Answer:
1. silicon
Step-by-step explanation:
The number of valence electrons in carbon and silicon is 4. The number of valence electrons in aluminium, oxygen and hydrogen are 3,2 and 1 respectively. Both carbon and silicon belong to group 14 in the periodic table. Both carbon and silicon share similar chemical and physical properties. Both carbon and silicon form four covalent bonds such as in CH₄ and SiH₄.