The alkali metals also react similarly with hydrogen to form ionic alkali metal hydrides, where the hydride anion acts as a pseudohalide: these are often used as reducing agents, producing hydrides, complex metal hydrides, or hydrogen gas.
ðɪ ˈælkəlˌaɪ mˈɛɾəlz ˈɔːlsoʊ ɹɪˈækt sˈɪmɪlɚli wɪð hˈaɪdɹədʒən tə fˈɔːɹm aɪˈɑːnɪk ˈælkəlˌaɪ mˈɛɾəl hˈaɪdɹaɪdz, wˌɛɹ ðə hˈaɪdɹaɪd ˈænaɪən ˈækts æz ɐ sˈuːdoʊhəlˌaɪd: ðiːz ɑːɹ ˈɔfən jˈuːzd æz ɹᵻdˈuːsɪŋ ˈeɪdʒənts, pɹədˈuːsɪŋ hˈaɪdɹaɪdz, kˈɑːmplɛks mˈɛɾəl hˈaɪdɹaɪdz, ɔːɹ hˈaɪdɹədʒən ɡˈæs.