An ion with 17 protons, 20 neutrons, and 18 electrons has a mass number of?
- oeman50Lv 71 decade agoFavorite Answer
17 protons and 20 neutrons add up to a molecular mass of 37, the electron mass is inconsequential.
- 4 years ago
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
- NorrieLv 71 decade ago
Electrons are not included in the mass number. Only Protons and Neutrons.
17 Protons and 20 Neutrons = an Atomic Mass Number of 37.
(A Stable Isotope of a Chlorine ion Cl(-1). Look it up if you must.
(In this case, although electrons are not considered in the Atomic Mass, the fact that it's an ion with 18 electrons makes it a negative particle. The only other substance with 18 electrons is the Noble gas Argon but, that also has 18 Protons and 22 neutrons).
Normal, Neutral chlorine has 17 electrons, 17 Protons and 18 Neutrons).
Stick your thumb where it will do more good....!!!
- 1 decade ago
COMPOSITION OF POLLUTION - FREE GROUND LEVEL AIR
COMPOSITION OF UNIVERSE
COMPOSITION OF EARTH
90 Naturally occurring
ATOM Chapter 3
What is it?
Def: The smallest particle still having the characteristics of an element. It is made up of smaller particles: electrons, protons, and neutrons.
Simplest atom is H (hydrogen).
1. Positive charge
2. "Weighs" 1 amu (atomic mass unit)
1 lb. = 273 x 1024 amu
3. The number of protons is the atomic number of an element.
4. The number of protons tells you what the element is.
5. What element has 6 protons?
6. How many protons in the element nitrogen (N)?
1. Negative charge
2. 1835 electrons weigh 1 amu.
3. Responsible for chemical bonds
1. No net charge
2. Weighs 1 amu
To get the atomic weight you add the number of protons and neutrons. When the protons and neutrons are considered as a unit, they are referred to as "nucleons".
Def. Average weight of all the atoms of an element.
Hydrogen has 1 proton and 1 electron, totaling 1 amu.
Deuterium has 1 proton (1 amu), 1 neutron (1 amu),
and 1 electron, totaling 2 amu.
Tritium has 1 proton (1 amu), 2 neutrons (2 amu), and 1 electron, totaling 3 amu.
Def: Atoms of the same element that have the same
atomic number but have different mass numbers.
The isotopes of an element all have the same number of protons but a different number of neutrons.
Hydrogen, deuterium and tritium are isotopes.
Tritium is radioactive.
ISOTOPES OF URANIUM
What does the 92 mean? What does the 238 mean?
X X = symbol of the element
Z Z = number of protons
A = mass number (number of protons and neutrons)
1H = hydrogen 2H = deuterium 3H = tritium
1 1 1
2 electrons can fit on the first level
8 electrons on the second
Atoms are happy when a shell or level is complete - will enter into reaction just to get the number of electrons for that shell.
When an atom does not have the same number of electrons and protons, it has a charge. This is an ion.
If an ion had 11 protons and 10 electrons, it would be a positive ion. These are called cations.
What element has 11 protons?
If an ion had 17 protons and 18 electrons, it would be a negative ion. These are called anions.
What element has 17 protons?
Atoms and Ions
Atoms have no net charge. They are neutral.
Ions have a charge, either positive or negative.
A positive ion has more protons than electrons. CATION
A negative ion has more electrons than protons. ANION
The ion of an atom has very different chemical properties than the atom or molecule. Sodium is a soft metal, which reacts with water and gives explosive hydrogen.
The sodium ion is half of table salt NaCl, which dissolves in water and is needed for human life.
- How do you think about the answers? You can sign in to vote the answer.
- 1 decade ago
mass number is the same as amount of protons plus amount of neutrons.
so, the mass must be 17 + 20 = 37
Although amount of protons isn't equal with electron, it only causes to be negative charge of atoms (ion)
- 1 decade ago
- Anonymous1 decade ago
atomic mas = protons+neutrons
- 1 decade ago
The atomic mass of chlorine would be 35.453, which you would just round to 35.