Answer:
Na2SO4 means: two moles sodium (45.98 g), one mole sulfur (32.06 g), and four moles oxygen (64.00 g) combine to form one mole of sodium sulfate (142.04 g).
Explanation:
The correct answers would be A, and D
The compound which is ionic is Kh
Kh is ionic because ionic compound is made between a metal and a non metal. K( potassium) is a metal while H (hydrogen) is a non metal. The bond between potassium and hydrogen form ionic bond whereby potassium loses one electron and hydrogen gain one electron to form an ionic compound.
Try to understand all the rules and laws like:
Aufbau Principle
Hund's rule
Pauli exclusion principle...
Then, you should understand the way in which you can fill the electrons in the orbitals!!