Mastering Biology Chapter 2 Flashcards

Questions and Answers

A substance that cannot be broken down into other substances by ordinary chemical procedures is a(n) _____.

element

What is the charge of a proton?

+1 charge

What is the charge of a neutron?

0 charge

What is the charge of an electron?

-1 charge Signup and view all the answers

Mass of ~1 amu is associated with a _ or a _.

proton, neutron Signup and view all the answers

Mass of ~1/2000 amu corresponds to an _____ .

electron Signup and view all the answers

What is the mass number of an ion with 104 electrons, 158 neutrons, and a +1 charge?

263 Signup and view all the answers

The innermost electron shell of an atom can hold up to _____ electrons.

2 Signup and view all the answers

Which of these relationships is true of an uncharged atom?

The number of protons is equal to the number of electrons. Signup and view all the answers

What determines the types of chemical reactions that an atom participates in?

the number of electrons in the outermost electron shell Signup and view all the answers

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?

6 Signup and view all the answers

Which of these refers to atoms with the same atomic number but different atomic masses?

These atoms are isotopes. Signup and view all the answers

Fluorine's atomic number is 9 and its atomic mass is 19. How many neutrons does fluorine have?

10 Signup and view all the answers

An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many protons does boron have?

5 Signup and view all the answers

Changing the number of _____ would change an atom into an atom of a different element.

protons in an atom Signup and view all the answers

The atoms of different phosphorus isotopes _____.

have different number of neutrons Signup and view all the answers

The type of bonding and the numbers of covalent bonds an atom can form with other atoms is determined by _____ .

the number of unpaired electrons in the valence shell Signup and view all the answers

What type of bond is joining the two hydrogen atoms?

covalent Signup and view all the answers

A(n) _____ refers to two or more atoms held together by covalent bonds.

molecule Signup and view all the answers

This atom can form up to _____ single covalent bond(s).

4 Signup and view all the answers

A(n) _____ bond joins these two oxygen atoms.

double covalent Signup and view all the answers

Atoms with the same number of protons but with different electrical charges _____.

are different ions Signup and view all the answers

In salt, what is the nature of the bond between sodium and chlorine?

ionic Signup and view all the answers

What is the result of the animated process?

a positively charged sodium ion and a negatively charged chlorine ion Signup and view all the answers

An ionic bond involves _____.

an attraction between ions of opposite charge Signup and view all the answers

What type of bond joins the carbon atom to each of the hydrogen atoms?

single (nonpolar) covalent Signup and view all the answers

The brackets are indicating a(n) _____ bond.

hydrogen Signup and view all the answers

What name is given to the bond between water molecules?

hydrogen Signup and view all the answers

A carbon atom and a hydrogen atom form what type of bond in a molecule?

nonpolar covalent bond Signup and view all the answers

An ionic bond is formed when _____ .

one atom transfers an electron to another atom Signup and view all the answers

Chemical equilibrium is reached when _____.

the forward and reverse reactions occur at the same rate so that the concentrations of reactants and products remain the same Signup and view all the answers

What does the term electron orbital describe?

An electron orbital describes a three-dimensional space where an electron can be found 90% of the time. Signup and view all the answers

What happens when two atoms form a chemical bond?

A chemical bond forms when two atoms transfer or share outer electrons to complete their outer shells. Signup and view all the answers

Which statement about weak bonds is correct?

Weak bonds are transient and easily reversible. Signup and view all the answers

Study Notes

Atoms and Elements

An element is a fundamental substance that cannot be broken down into simpler substances through chemical means.
Protons carry a positive charge (+1) and are denoted by the symbol p.
Neutrons have no charge (0) and are represented by the symbol n.
Electrons possess a negative charge (-1) and use the symbol e.

Atomic Mass and Structure

Protons and neutrons each have a mass of approximately 1 atomic mass unit (amu).
Electrons have a negligible mass, approximately 1/2000 amu.
The mass number for an ion with 104 electrons, 158 neutrons, and a +1 charge is 263.
The innermost electron shell of an atom can accommodate a maximum of 2 electrons.

Charged Atoms and Isotopes

An uncharged atom contains an equal number of protons and electrons.
The atomic number of an atom with 6 protons, 6 neutrons, and 6 electrons is 6.
Atoms with the same atomic number but different atomic masses are known as isotopes.
Fluorine, with an atomic number of 9 and atomic mass of 19, has 10 neutrons.

Electron Configuration

An uncharged atom of boron, with an atomic number of 5 and atomic mass of 11, has 5 protons.
Changing the number of protons in an atom transforms it into a different element.
Different isotopes of phosphorus have varying numbers of neutrons.

Chemical Bonding

The nature of bonding and the number of covalent bonds an atom can form depend on the number of unpaired electrons in the valence shell.
A bond joining two hydrogen atoms is a covalent bond.
A molecule is formed when two or more atoms are held together by covalent bonds.
Carbon can form up to 4 single covalent bonds.
A double covalent bond occurs between two oxygen atoms.

Ionic Bonds

Atoms with the same number of protons but different electrical charges are classified as ions.
In sodium chloride (salt), the bond between sodium and chlorine is ionic.
The result of interactions in salt formation is a positively charged sodium ion and a negatively charged chlorine ion.
An ionic bond arises from the attraction between ions of opposite charges.

Types of Bonds in Molecules

Carbon and hydrogen form a single (nonpolar) covalent bond.
Hydrogen bonds, indicated by brackets, label interactions between molecules like water.
The bond between water molecules is also a hydrogen bond.
An ionic bond occurs when one atom transfers an electron to another.

Chemical Equilibrium and Electron Orbitals

Chemical equilibrium is established when forward and reverse reactions take place at the same rate, maintaining constant reactant and product concentrations.
An electron orbital describes the three-dimensional region where an electron is likely to be found 90% of the time.
A chemical bond forms when two atoms either transfer or share outer electrons to complete their valence shells.

Characteristics of Weak Bonds

Weak bonds are typically transient and easily reversible, allowing for dynamic interactions in molecular biology.

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Description

Test your knowledge of key terms and concepts from Chapter 2 of Mastering Biology. This quiz covers essential definitions and symbols associated with fundamental biological elements. Perfect for reinforcing your understanding of basic biology concepts.