1. If an atom of calcium has a mass of 40: a. Protons =
b. Neutrons =
2. If an atom of krypton has a mass of 84:
a. Protons =
b. Neutrons =
3. If an atom of tin haſ a mass of 119:
a. Protons =
b. Neutrons =
4. If an atom of tungsten has a mass of 184:
a. Protons
b. Neutrons =

1. If an atom of calcium has a mass of 40:

a. Protons = 20

b. Neutrons = 20

2. If an atom of krypton has a mass of 84:

a. Protons = 36

b. Neutrons = 48

3. If an atom of tin has a mass of 119:

a. Protons = 50

b. Neutrons = 69

4. If an atom of tungsten has a mass of 184:

a. Protons = 74

b. Neutrons =110

what are the choices?

answer is: empirical formula is tl₂o. if we use 100 grams of compound, tha:

m(tl) = 96.2%  · 100 g ÷ 100%.

m(tl) = 96.2 g.

n(tl) = m(tl)  ÷ m(tl). n(tl) = 96.2 g  ÷ 204.4 g/mol.

n(tl) = 0.47 mol. m(o) = 3.77 g. n(o) = m(o)  ÷ m(o). n(o) = 3.77 g  ÷ 16 g/mol. n(ag) = 0.235 mol. n(tl) . n(o) = 0.47 mol : 0.235 mol /0.235. n(tl) . n(o) = 2 : 1.

m(tl₂o) = 204.4 g/mol  · 2 + 16 g/mol = 424.8 g/mol.

m(compound) = 456. 8 g/mol - 424.8 g/mol = 32 g/mol ( 2 oxygens); tl₂o₃.