Question
A two-dimensional solid pattern formed by two different atoms X and Y is shown below. The black and white squares represent atoms X and Y respectively. the simplest formula for the compound based on the unit cell from the pattern is
- $XY _8$
- $X _4 Y _9$
- $XY _2$
- $XY _4$

- $XY _8$
- $X _4 Y _9$
- $XY _2$
- $XY _4$