2-1 BIO-1010 Study Guide Flashcards
What are the three basic types of subatomic particles in an atom?
Protons, neutrons, and electrons.
How are protons, electrons, and neutrons different in terms of their mass, charge, and location within an atom?
Protons: Positive charge, in nucleus, heavy. Neutrons: No charge, in nucleus, similar mass to protons. Electrons: Negative charge, in clouds, very light mass.
What is meant by isotopes of an atom?
Atoms with the same number of protons but different numbers of neutrons.
What is the half-life of a radioactive isotope?
The time for half of the radioactive atoms in a sample to decay.
What does the octet rule tell us about electrons in an atom?
Atoms are stable when they have 8 electrons in their outer shell.
How does an atom become a positive or negative ion?
By losing electrons (positive) or gaining electrons (negative).
What is an ionic bond?
A bond formed between a positive ion and a negative ion.
What does pH measure?
The concentration of hydrogen ions (H⁺) in a solution.
What is the pH of a neutral solution (distilled water)?
pH 7.
What is a covalent bond?
A bond where two atoms share a pair of electrons.
What is the difference between non-polar and polar covalent bonds?
Non-polar: Electrons shared equally. Polar: Electrons shared unequally.
Why do hydrogen bonds form, and why is water so good at this?
Hydrogen bonds form between slight positive and negative regions; water is polar, making it good at forming hydrogen bonds.
__________ is everything that has mass (weight) and takes up space.
Matter
Matter is made up of about 100 pure substances called __________.
Elements
The smallest bit of any element is called an __________.
Atom
__________ have a positive charge and are found in the atom’s nucleus.
Protons
__________ have no charge and are also found in the atom’s nucleus.
Neutrons
__________ are found in “clouds” surrounding the nucleus and have a negative charge.
Electrons
The number of __________ in an atom determines what type of element it is.
Protons
Different __________ of an atom have the same number of protons but different numbers of neutrons.
Isotopes
The cloud or shell closest to an atom’s nucleus has room for only __________ electrons.
2
The next two shells farther out have room for __________ electrons.
8
An atom of sulfur (atomic number 16) has __________ electrons in its first shell, __________ electrons in its second shell, and __________ electrons in its third (outer) shell.
2, 8, 6
When an atom such as potassium loses the only electron in its outer shell, it becomes a __________.
Positive ion
