If both the president and the vice president can no longer serve, who will become the next head of state?

In the case that the president can no longer serve, the vice president would serve as president.

Explanation:

If the vice president cannot serve, the line of succession falls to the speaker of the House, then to the Senate president pro tempore, then to Cabinet members.

i disagree that there is little difference between adult female development and adult male development. sociological studies comparing female and male pathways to adulthood, revelead that there are sustancial differences between them. particularly, female and male differ from timing of marriage, when they began to live with children and the likelihood of combining wife/husband and parent roles.