Is it summer everywhere at the same time?

No.

In the northern hemisphere, summer is consider to be around June/July/August.

In the Southern Hemisphere, it is the opposite: summer is in the months of December/January/February.

In some areas such as near the equator, the seasons themselves differ. For example, where I live, we have three seasons: wet season, dry season, and build up.

Hope this helps.

This is what i found on google “lithium and sulfide can react together to form litium sulfide(li2s). when lithium sulfide hydrolyses(breaks down) in air, it releases hydrogen sulfide which is characteristized by a rotten egg odor.” i hope this you for what your looking for