How do you say elements in Japanese?

If you mean chemical elements it would be 元素 /gen so/. If you mean 'factor, component, element' it would be 要素 /you so/.

If your query is of the five elements in Japanese they are as follows:

Kanji/Meaning..........Single Reading...........Reading in Compound Nouns....

火 (Fire).............. hi (like 'he' in English).............ka........................................

水 (Water)........................mizu........................sui........................................

土 (Earth).........................tsuchi.......................do........................................

雷 (Lightning)..................kaminari.....................rai.......................................

風 (Wind)..........................kaze.......................fuu........................................