Atomic
number
number
Where can you find the atomic number in the periodic table?
Typically, in the upper left corner of each element.
What is the mass number?
The number of protons and neutrons that an atom has
How many neutrons does Hydrogen-3 (3H) has?
2 neutrons
Where can you find the atomic weight in the periodic table?
Typically, in the upper right corner of each element.
What is an ion?
An atom or a molecule that obtained net electric charge by gaining or losing electrons.
What is the atomic number?
The number of protons that an atom has
What are isotopes?
Chemical species of the same element that have different mass numbers
How many neutrons does Boron-11 (11B) has?
6 neutrons
What is the unit that is used to measure atomic weight?
Atomic Mass Unit (amu)
According to its electric charge, ions classify as:
Anions (negative charge) and cations (positive charge)
What is the atomic number of Krypton (Kr)?
36
What is the mass number of Aluminum-27 (27Al)
27
How many neutrons does Gold-197 (197Au) has?
118 neutrons
What is the atomic weight of Silver (Ag)?
107.87 amu
We have the ions Na+ and Cl-, which of them lost an electron? Which gained an electron?
Na+ lost an electron and Cl- gained an electron
An atom has 53 protons, what's its atomic number? What element is this?
Z=53, Iodine (I)
An atom has 12 protons and 13 neutrons. What is the mass number? To which element belongs?
A=25, Magnesium (Mg)
Calcium has five stable isotopes: 42Ca, 43Ca, 44Ca, 46Ca and 48Ca. 42Ca has 22 neutrons, how many neutrons do the rest of the isotopes have?
23, 24, 26 and 28 neutrons
A chemical element has two isotopes: Isotope A has an atomic mass of 10 amu and its abundance is 60%, on the other hand, isotope B has an atomic mass of 11 amu and an abundance of 40%. What is the atomic weight of the element?
10.4 amu
It lost 2 electrons and it's a cation.
Atoms from one particular chemical element have __________ atomic number, although their mass number is ________.
Same, different
Berilium - 13 (13Be) is a radioactive isotope that emits neutrons. What's the mass number of this isotope? If 13Be emits 1 neutron, what will be the mass number of the resulting isotope?
The mass number of 13Be is 13, if it emits a neutron, the mass number of the resulting isotope will be 12 (12Be)
If we break Uranium-235 (235U) we obtain Barium-144 (144Ba) and Krypton - 89 (89Kr). How many neutrons do every isotope have?
235U has 143 neutrons, 144Ba has 88 neutrons and 89Kr has 53 neutrons.
A chemical element has three isotopes: Isotope A has an atomic mass of 12 amu and its abundance is 20%, isotope B has an atomic mass of 13 amu and an abundance of 50% and isotope C has an atomic mass of 14 amu with an abundace of 30%. What is the atomic weight of the element?
13.1 amu
Explain how an atom can lose and gain an electron