Chapter 2 Flashcards
Define atom: How are electrons arranged on the valence shell; valence electrons Define and know examples of chemical bonds (ionic, covalent, hydrogen); Define pH (H+ concentration); know the pH scale- acid <7, neutral 7, base < 7 Describe the major monomers and polymers (these are formed and broken down by dehydration synthesis and hydrolysis), Define metabolism (catabolism and anabolism), Describe the aerobic respiration reaction
What subatomic particles do atoms consist of?
Protons (positively charged) are found in the nucleus.
Neutons (neutral) are found in the nucleus.
Electrons (negatively charged) are found in shells orbiting the nucleus.
What defines an atom’s atomic number?
The number of protons in the nucleus defines an atom’s atomic number.
What determines which element an atom is?
The number of protons determines which element an atom is.
What happens if the number of protons in an atom changes?
If the number of protons changes, the atom becomes a different element.
How are electrons arranged around the nucleus?
Electrons are arranged in energy levels (shells) around the nucleus.
What are valence electrons?
Valence electrons are the electrons in the outermost shell of an atom. They determine an atom’s reactivity and bonding behavior.
How many electrons can fit in the first shell?
Two electrons fit in the first shell.
How many electrons can fit in the second shell?
Eight electrons can fit in the second shell.
How many electrons can fit in the third shell?
Eighteen electrons can fit in the third shell, however most elements are stable with having only 8).
How are ionic bonds formed?
Ionic bonds are formed when one atom transfers electrons to another, creating charged ions that attract each other.
Which bonds form a new substance?
Ionic and covalent bonds form new substances by allowing atoms to share or transfer electrons, creating new compounds with distinct properties.
What bond connects already existing molecules or bonds thus stabilizing their structure?
Hydrogen bonds connect already existing molecules thus stabilizing their structure by holding them in a specific arrangement.
How are covalent bonds formed?
Covalent bonds are formed when atoms share one or more pairs of electrons.
What are hydrogen bonds?
Hydrogen bonds are weak attractions between a slightly positive hydrogen atom and a slightly negative atom (like oxygen or nitrogen.
What is pH?
pH is a measure of hydrogen ion concentration (H+) in a solution that indicates how acidic or basic a substance is.
How does the pH scale work?
The pH scale is logarithmic, so each unit change represents a tenfold difference in H+ concentration.
What is the pH range for acids?
Acids have a pH of less than 7 and a higher H+ concentration.
What is the pH of a neutral solution?
A neutral solution has a pH of 7, where H+ and OH- concentrations are equal.
What is the pH range for bases?
Bases have a pH greater than 7 and a lower H+ concentration.
