Learn Arabic (Modern Standard): استكشفنا الجبل ووجدنا الغاز. - We explored the mountain and found the gas.

It comes from the root ك ش ف (to reveal or uncover). Form X verbs usually start with استـ (ista-) and often mean seeking or trying to do the action of the root. Here, seeking to uncover becomes exploring. The ـنا (-na) at the end shows it is conjugated for we in the past tense.

Why do both verbs in this sentence end in ـنا?

The suffix ـنا (-na) is the past tense marker for we. In Arabic, past tense conjugation happens by adding suffixes to the end of the verb. It attaches to the Form X base استكشف (he explored) to make استكشفنا (we explored), and to the Form I base وجد (he found) to make وجدنا (we found).

Why is the word for and attached directly to the second verb?

The word for and is the single letter و (wa). In Arabic, one-letter words like this are never written on their own with spaces around them. They must be physically attached to the beginning of the next word, resulting in ووجدنا (and we found).

Is the word الغاز (the gas) related to the English word?

Yes, غاز (ghaz) is a loanword borrowed directly from European languages. It behaves exactly like a regular Arabic noun, easily taking the definite article prefix الـ (al-) to mean the gas.