Anonymous

1) Calculate the mass of a neutral deuterium atom. Use the following::

1 proton = 1.6726 X 10 ^ -24 g

1 neutron= 1.6749 X 10 ^ -24 g

1 electron= 9.1094 X 10 ^ -28 g

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2) write the symbols for the atom or ion with each of the following set of subatomic particle:::

a) 17p, 18 n, 16 e

b) 17p, 18n, 17 e

c) 17p, 20n, 18e

(p = proton, n=neutron, e=electrons

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• Dr W
Lv 7

neutral means this.. the # protons = # neutrons

deuterium is an isotope of hydrogen having 1 proton and 1 neutron... so it's mass is...

1 x 1.6726 X 10 ^ -24 g + 1 x 1.6749 X 10 ^ -24 g + 1 x 9.1094 X 10 ^ -28 g = 3.3484 x 10^-24 g

did you notice that the mass of electron was << mass of a proton or a neutron? and the the proton was about = neutron?

for this reason, electrons are generally ignored in atomic masses from the periodic table...and

# protons = atomic number

# neutrons = atomic mass - # protons = atomic mass - atomic number

# electrons = # protons for a neutral atom.

**** 2 ****

17 P means the atomic number = 17. the element with atomic number = 17 is chlorine

a) atomic mass = # protons + # neutrons = 35. 17 p and 16 e gives it a +1 charge. this is because the p as a +1 charge and the e's have a -1 charge... 17 x +1 - 16x -1 = +1... so the element is 35 Cl +1

b) atomic mass = 17 + 18 = 35.. 17 p and 17 e means it has a neutral charge. element is 35 Cl

c) atomic mass = 17 + 20 = 37... 18e and 17 p give it a -1 charge. 37 Cl -1

If you do some basic research or look up wikipedia you will find that ordinary Hydrogen 1H has one proton and one electron, Deuterium 2H has one proton, one neutron and one electron since you have the masses of the individual nuclides you can add them up and do the math.

2. they all have 17 protons so find the atomic number 17 on the periodic table. Both a and b have an extra neutron so they will be an Isotope so the atomic mass will be 17+18=35 and c has 3 extra neutrons so the mass no is 37. a. has lost one electron so it is an ion with a charge of +, b. has equal nos of p and e so it is neutral. and c. has gained one electron so it will have a charge of -.

The symbol is superscript mass Name of the element superscript charge eg. for carbon 14 ion 14C- (14 and - should be superscript)

I am not sure if you have read your texts. I would encourage you to read basic atomic chemistry and seek help from your tutor

Not sure about the first part, but on the second question add the protons and neutrons together and find the element with the same number for their atomic mass.