Chapter 2- Chemical Composition Of Body Flashcards
What are chemical elements?
Each type of atom–carbon, hydrogen, oxygen, etc. is called a chemical element
What is an atom composed of?
Protons, neutrons, and electrons
The atomic nucleus is composed of what?
Protons and neutrons are confined to the atomic nucleus
What are orbitals?
The orbitals are where the electrons revolve around the nucleus. Each orbital can hold two electrons.
What is an atomic number?
An atomic number is the specific number of protons that a chemical element contains
What’s atomic weight?
Atomic weight is an atom’s mass relative to the mass of other atoms measured in daltons
What are isotopes?
Isotopes are multiple forms of an atom, that does not have the same number of neutrons and protons.
What is gram atomic mass?
Gram atomic mass is the amount of an element in grams, equal to the numerical value of its atomic weight
What is an ion?
When an atom gains or loses one or more electrons and acquires a net electrical charge. Ions with a net positive charge are called cations and those with a net negative charge are called anions
What are electrolytes?
Ionic forms of mineral elements that are able to conduct electricity when dissolved in water
What are trace elements?
Thirteen essential elements present in small quantities but are essential for normal growth and function
What’s a molecule?
A molecule is two or more atoms bonded together
What’s a compound?
A molecule made up of two or more different elements
What’s a covalent bond?
The strongest bond between two atoms which forms when one or more electrons transfer from the outer energy shell of one atom to that of another, or when two atoms with partially unfilled electron orbitals share electrons
What is electronegativity?
It’s the measure of an atom’s ability to attract electrons in a covalent bond
What is a polar covalent bond?
A covalent bond where the more electronegative atom acquires a slight negative charge, whereas the other atom, having partly lost an electron, becomes slightly positive
What are polar molecules?
Polar molecules have polar covalent bonds and tend to be more soluble in water
What are nonpolar covalent bonds?
A bond where the electrons are equally or nearly equally shared by the two atoms.
What are nonpolar molecules?
Nonpolar molecules contain high proportions of nonpolar covalent bonds and tend to be less soluble in water
What are hydrogen bonds?
Hydrogen bonds are formed when two polar molecules are in close contact, and an electrical attraction forms between them. Weakest of bonds but when large numbers are present, they play a major role in the shape of large molecules
What are atoms?
The units of matter that form all chemical substances
