Question

write the chemical symbols for three different atoms or atomic anions with 35 electrons.

Explanation:

Step1: Recall atomic number and electron - count relationship

In a neutral atom, the number of electrons is equal to the atomic number. For an anion, the number of electrons is the atomic number plus the negative charge. The element with atomic number 35 is bromine (Br). A neutral bromine atom has 35 electrons.

Step2: Consider anions with 35 electrons

We can consider anions formed by elements with atomic numbers less than 35. For example, selenium (Se) has an atomic number of 34. When it gains one electron to form the selenide anion ($Se^-$), it has 34 + 1=35 electrons. Another example is arsenic (As) with atomic number 33. When it gains two electrons to form the arsenide anion ($As^{2 - }$), it has 33+2 = 35 electrons. And the neutral bromine atom (Br) also has 35 electrons.

Answer:

$Br$, $Se^-$, $As^{2 - }$