Please help me, Thank you!

2

Explanation:

The atom shown in the image has 2 core electrons.

Electrons are the negatively charged particles within an atom. Therefore the total number of electrons surrounding the nucleus in the given specie is 7.

 So;

   We have 2 core electrons

   And 5 valence electrons

The core electrons are the inner orbital electrons.

The valence electrons are the outermost electrons.

both adhesion and cohesion are attractions.

they are different in that adhesion is the force of attraction between the molecules of two different substances, whereas cohesion is the force of attraction between molecules of the same substance.

possible examples include capillary action, in which the adhesion between water and glass causes the water to rise in a narrow tube against the force of gravity.

because of hydrogen bonding, water is extremely cohesive.

this causes molecules on the surface of water to be drawn inward, which is why drops of water form beads on smooth surfaces.

hope this .

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