Chapter 2 Flashcards
Where are protons and neutrons?
In the nucleus.
Where are the electrons?
In the electron shell.
What is the atomic number determined by?
The number of protons.
True or false: protons determine nothing and electrons determine the mass.
False. Protons determine the identity of the substance. Electrons do determine the mass.
What is an isotope?
It is a substance with various neutrons. For example, carbon 12 is stable because it is 6+6. Carbon 13 is not stable because it is 6+7.
What is radioactive decay?
Unstable isotopes break into particles.
True or false: there are three types of chemical bonds.
True.
What is a covalent bond?
Two atoms share one or more pairs of electron.
What is an ionic bond?
They are formed between oppositely charged electrons
What is a hydrogen bond?
Polarity of water results in weak electrical attractions.
True or false. The life supporting properties of water are the ability to store heat and it is a good solvent.
True. Storing heat in the body prevents over heating and being a good solvent aids chemical reactions.
What is the difference between hydrophobic and hydrophilic molecules? List some examples.
Hydrophobic avoids water molecules and hydrophilic is attracted to water molecules. Hydrophobic= lipids, Hydrophilic= sugar
What does pH measure?
Concentration of hydrogen ions.
What is an acid’s number on the pH scale and why?
An acid is below a 7 because it adds hydrogen ions into a solution.
What is a base’s number on the pH scale and why?
A base is above a 7 because it removes hydrogen ions from a solution.
