Lec. 1 - Atoms and Molecules Flashcards
Describe an atom, explain protons, neutrons, and electrons.
An atom is an extremely small particle that is what MATTER is composed of. A PROTON is a component of the nucleus with a POSITIVE charge. A NEUTRON is the other part of the nucleus and has a NEUTRAL charge. And an ELECTRON is on the outside of the nucleus on the rings of the atom and has a NEGATIVE charge.
Explain what defines an element; how are they arranged in the periodic table?
An element is defined by its atomic number, which equals the number of protons in the element. Elements are arranged by their increasing atomic number. .
Explain what an isotope is, compare with elements.
An isotope is an atom of a single element that possesses a different number of neutrons but same number of protons.
Describe how electrons are arranged around the nucleus.
Electrons are arranged around the nucleus in an ELECTRON CLOUD, and atoms always want 8 electrons in the outermost shell. Orbitals are the areas electrons occupy.
Explain the importance of valence electrons.
Valence electrons of atoms are what bond atoms to one another. The number of valence electrons is what determines how atoms bond.
Describe how chemical bonds are formed; explain the role of electrons in this process.
Chemical bonds are formed when atoms share or transfer valence electrons; atoms want a full valence shell so they will transfer electrons in order to accomplish that.
Describe how ions are formed and give examples.
Ions are formed when forces maintaining the number of electrons are overcome by another force, causing an atom to loose one or more electrons.
