Bluebirds and blue jays, two bird species live in a small wooded area. The blue jays are very aggressive and eventually take over the nests of the bluebirds. This is an example of interspecific.

so here we go

atomic mass

239 + 1 = y + 134 + 3 combine like terms

240 = y + 137             subtract 137 from both terms

240 - 137 = y

103 = y

atomic number

94 = z +54 + 0

94 = z + 54               subtract 54 from both sides.

40 = z

answer

d) a person who learns about the world by observing it.

explanation:

scientist are people who discover why and how things are done and made in the world.