Review for unit test

Question 1

What are the two main groups of matter?

Answer 1

Pure substances and mixtures

Question 2

What are elements?

Answer 2

Fundamental substances listed in the periodic table, each consisting of a specific type of atom.

Question 3

What are compounds?

Answer 3

Formed from groups of different atoms bonded together.

Question 4

What are homogeneous mixtures?

Answer 4

Mixtures with one visible component, such as saltwater.

Question 5

What are heterogeneous mixtures?

Answer 5

Mixtures with two or more visible parts, such as salad.

Question 6

What are physical properties?

Answer 6

Characteristics that can be observed directly, such as color, luster, malleability, ductility, hardness, boiling point, and melting point.

Question 7

What are chemical properties?

Answer 7

Describe how a material reacts with other substances, such as wood being combustible or sodium reacting violently with water.

Question 8

What are physical changes?

Answer 8

Occur when a material changes shape or form without producing new materials, such as ice melting or sugar dissolving in water.

Question 9

What are chemical changes?

Answer 9

Occur when a material undergoes a reaction that produces a new substance, such as the rusting of iron.

Question 10

What are the three subatomic particles?

Answer 10

Protons, neutrons, and electrons.

Question 11

Where are protons and neutrons located in an atom?

Answer 11

In the nucleus.

Question 12

Where are electrons located in an atom?

Answer 12

Outside the nucleus.

Question 13

What is the atomic number?

Answer 13

The number of protons in an atom.

Question 14

What is the mass number?

Answer 14

The sum of protons and neutrons in an atom.

Question 15

What are valence electrons?

Answer 15

Electrons in the outermost shell of an atom.

Question 16

What is an ion?

Answer 16

A charged atom formed by gaining or losing electrons.

Question 17

What is a cation?

Answer 17

A positively charged ion formed by losing electrons.

Question 18

What is an anion?

Answer 18

A negatively charged ion formed by gaining electrons.

Question 19

Why do atoms form ions?

Answer 19

To achieve a stable electron configuration, often by having a full outer shell.

Question 20

What is hyponatremia?

Answer 20

condition caused by low sodium levels in the blood, often due to excessive water consumption.

Question 21

What are some essential ions in the body?

Answer 21

Calcium, phosphorus, and iron ions.

Question 22

How do alkali metals form ions?

Answer 22

By losing one electron to form a +1 cation.

Question 23

How do halogens form ions?

Answer 23

By gaining one electron to form a -1 anion.

Question 24

What are ions?

Answer 24

Charged atoms formed by gaining or losing electrons.

Question 25

What are the two main types of ions?

Answer 25

Cations (positive) and anions (negative).

Question 26

How do metals typically form ions?

Answer 26

By losing electrons to form cations.

Question 27

How do nonmetals typically form ions?

Answer 27

By gaining electrons to form anions.

Question 28

What is ionic bonding?

Answer 28

The attraction between positively charged cations and negatively charged anions.

Question 29

Why do atoms form ions?

Answer 29

To achieve a stable electron configuration, often by having a full outer shell.

Question 30

What is the role of calcium ions in the body?

Answer 30

Calcium ions are important for neurotransmitter function, enzyme activity, muscle contraction, and bone formation.

Question 31

What is an ionic bond?

Answer 31

A bond formed by the transfer of electrons between a metal and a nonmetal.

Question 32

What is the role of magnesium ions in the body?

Answer 32

Magnesium ions are essential for ATP function, DNA and RNA formation.

Question 33

What is a covalent bond?

Answer 33

A bond formed by the sharing of electrons between two nonmetals.

Question 34

What is a Lewis dot diagram?

Answer 34

A diagram that shows the valence electrons of an atom as dots.

Question 35

What is electronegativity?

Answer 35

Electronegativity is a measure of an atom's ability to attract electrons.

Question 35

How can you tell if a bond is ionic or covalent?

Answer 35

Ionic bonds typically form between a metal and a nonmetal, while covalent bonds form between two nonmetals. You can also look at the electronegativity difference between the atoms.

Question 36

What is a chemical formula?

Answer 36

A representation of a molecule or compound that shows the types and numbers of atoms present.

Question 37

Formula of water??

Answer 37

H2O

Question 38

Formula of Carbon dioxide??

Answer 38

CO2

Question 39

Formula of sodium chloride??

Answer 39

NaCl

Question 40

Ionic Compounds

Answer 40

Strong electrostatic forces, high melting/boiling points, hard/brittle, conduct electricity in solution

Question 41

Molecular Compounds

Answer 41

Weak intermolecular forces, low melting/boiling points, soft/flexible, poor conductors of electricity

Question 42

steps of writing chemical formulas

Answer 42

identify cation and anion, balance charges, write formula

Question 43

Naming Ionic Compounds

Answer 43

Write cation name, write anion name (-ide for nonmetals), combine names

Question 44

Multivalent Metals

Answer 44

Use Roman numerals to indicate charge (e.g., Fe²⁺ is iron(II))

Question 45

Covalent Bonding

Answer 45

Sharing of electrons between nonmetals

Question 46

Lewis Dot Structures

Answer 46

Represent valence electrons as dots around the element symbol

Question 47

Law of Conservation of Mass

Answer 47

Matter cannot be created or destroyed, total mass of reactants = total mass of products

Question 48

Counting Atoms in Chemical Formulas

Answer 48

Use subscripts to determine the number of atoms of each element

Question 49

Balancing Chemical Equations

Answer 49

Adjust coefficients to equalize the number of atoms of each element on both sides

Question 50

Decomposition Reaction

Answer 50

AB → A + B

Question 50

Synthesis Reaction

Answer 50

A + B → AB

Question 51

Single-Replacement Reaction

Answer 51

A + BC → AC + B

Question 52

Double-Replacement Reaction

Answer 52

AB + CD → AD + CB

Question 53

Combustion Reaction

Answer 53

Fuel + O₂ → CO₂ + H₂O + energy

Question 54

Acids

Answer 54

Sour taste, corrosive, turns blue litmus red

Question 55

Bases

Answer 55

Bitter taste, slippery, turns red litmus blue

Question 56

Neutralization Reaction

Answer 56

Acid + Base → Salt + Water

Question 57

rules for naming binary acids

Answer 57

Hydro + nonmetal stem + ic acid (e.g., HCl: hydrochloric acid).

Question 58

rules for naming oxyacids

Answer 58

Nonmetal oxide + water. If polyatomic ion ends in -ate, acid ends in -ic acid; if -ite, acid ends in -ous acid (e.g., H₂SO₄: sulfuric acid).

Question 59

pH Scale

Answer 59

7 is neutral, <7 is acidic, >7 is basic