Lecture 2 Chemistry Flashcards
Define an Atom ?
Atoms are functional building blocks of all substances that are composed of Protons, Neutrons and Electrons,
and
smallest particle of an element
Name the 3 subatomic particles , there charges and mass.
Electron 1- , o mass
Proton 1 +, 1 mass
Neutron 0, 1 mass
What is the difference between an Atom and an element
An atom is the smallest chemical unit
Define Element?
substance made of atom with the same number of protons. Can not be broken down by simpler substances.
The atomic number of the element carbon is 6; this means that it has…? (choose the best answer)
(A) 6 protons in its nucleus
(B) 6 electrons in its nucleus
(A) - 6 protons in its nucleus
Define Isotope ?
A variation of a chemical element that have the same protons but differ in the number of neutrons
(Change in atomic mass, but not charge)
What is a radioactive isotope?
isotopes with an Unstable Nucleus
What is radioactive decay?
A period of time where one-half of the radioactive emits energy and releases subatomic particles
Define Half Life ?
The period of time in which half of a radioactive substance decays.
What does PET stand for and what is it?
Positron emission tomography/ uses radioactive tracers to detect tumors of inflammation
Medical imaging modality that allows imaging of metabolic processes within the body?
A) PET
B) FDG
C) Radioisotope
A) PET
Subatomic particles that travel around the nucleus in different orbits are called _____?
Electron
Valence electrons in the outermost shell are ____available for bonding ?
A) chemicals
B) electrons
B) Electrons
T/F - Each electron level of an electron shell holds eight electrons.
F) They hold 2 in the inner shell and then up to 8
If phosphorus has an atomic number of 15, how many electron shells does a phosphorus atom have?
A phosphorus atom has 15 electrons orbiting its nucleus; therefore, it would require 3 electron shells to hold them, with the outer shell being filled by only 5 electrons.
Which system is best specifically for the ability to detect and stage many forms of cancer non-invasively
PET - uses radioactive tracers to detect tumors and inflammation
Why do electrons matter ?
Electrons determine an atoms chemical behavior
Choose all that apply for Valence Electron :
A- The electrons in the outermost energy level are called valence electrons
B- A valence electron holds only 2 electrons in the outermost shell
C- An electron in an outer shell of an atom can participate in forming chemical bonds with other atoms.
D- A and C
E- A and B
D - A and C , The electrons in the outermost energy level are called valence electrons and An electron in an outer shell of an atom can participate in forming chemical bonds with other atoms.
Which group has molecules containing atoms of two or more elements?
A- Molecules
B- Compound
B- Compound
Which one has a group of two or more atoms joined together by chemical bonds ?
A- Molecules
B- Compound
A- Molecules
T/F A Chemical Bond has an attractive force between two atoms when their electrons interact?
True
_____ bonds occur between elements that are closer together on the periodic table?
A- Ionic bond
B- Covalent bond
B- Covalent bond
____ bonds occur farther from each other in the periodic table ?
A- Ionic bond
B- Covalent bond
A- Ionic bond
What are the three types of chemical reactions?
Synthesis , Decomposition , and Exchange
