Chemistry Fall Final Flashcard

Front

What is the average atomic mass of an element with isotopes of 75.23 amu (24.1%), 74.61 amu (48.7%), and 75.20 amu (27.2%)?

Back

74.92 amu

Front

How many neutrons are in the isotope No-254?

Back

152

Front

Dot diagrams are used to represent what?

Back

Outer level electrons

Front

Which family of elements contains the most reactive metals?

Back

Alkali metals

Front

In a chemical formula, what are the numbers that show the number of each type of atom called?

Back

Subscripts

Front

What is the definition of isotopes?

Back

Isotopes are atoms of the same element that have the same number of protons but different numbers of neutrons.

Front

What is the significance of subscripts in a chemical formula?

Back

Subscripts indicate the number of atoms of each element in a compound.

Front

What are alkali metals?

Back

Alkali metals are highly reactive metals found in Group 1 of the periodic table.

Front

What is the atomic number of an element?

Back

The atomic number is the number of protons in the nucleus of an atom.

Front

What is the difference between atomic mass and atomic weight?

Back

Atomic mass is the mass of a single atom, while atomic weight is the average mass of an element's isotopes.