Calcium oxide
Calcium phosphate
Sodium phosphate
Sodium silicate
Answer is Wrong!
Answer is Right!
The correct answer is $\boxed{\text{silicon dioxide}}$.
Calcium oxide is $\ce{CaO}$, calcium phosphate is $\ce{Ca3(PO4)2}$, sodium phosphate is $\ce{Na3PO4}$, and sodium silicate is $\ce{Na2SiO3}$.
Quartz is a mineral composed of silicon and oxygen. It is the most common mineral in the Earth’s crust, and it
is found in many different forms, including sand, granite, and quartzite. Quartz is a very hard mineral, and it is used in many different products, including glass, ceramics, and electronics.