Physical Science Chapter 4 & 5

Question 1

Valence electrons

Answer 1

The amount of electrons on an elements outer shell

Question 2

Force of attraction that holds atoms together as a result of the rearrangement of electrons between them

Answer 2

Chemical bonds

Question 3

Periods

Answer 3

Horizontal Rows on periodic table

Question 4

An atom or group of atoms that has an electric charge

Answer 4

Ion

Question 5

How do ions form

Answer 5

When a neutral atom loses a valence electron it loses a negative charge and becomes a positive ion. When a neutral atom gains electrons it gains a negative charge and becomes negative

Question 6

Atoms that are made of more than one Atom

Answer 6

Polyatomic ions

Question 7

Attraction between two oppositely charged ions

Answer 7

Ionic bond

Question 8

Result of ions bonding

Answer 8

Ionic compound

Question 9

How are the formulas and names of ionic compounds written

Answer 9

First the symbol of positive ion then the negative ion then add subscripts

Question 10

Tell is the ratio of elements in a compound

Answer 10

Subscripts

Question 11

What are properties of ionic compounds

Answer 11

Ionic compounds form hard brittle crystals that have high melting points and conduct electric current when dissolved or melted

Question 12

The ionic compounds that form solids by building up repeating patterns of ions

Answer 12

Crystal

Question 13

How do ionic compounds(crystals) melt

Answer 13

The ions in the crystal have to melt have to break apart for an ionic compound to melt which is only caused by melting

Question 14

The chemical bond formed when 2 atoms share electrons

Answer 14

Covalent bond

Question 15

How are atoms held together in a covalent bond

Answer 15

The attraction between the shared electrons and the protons in the nucleus of each atom hold the atoms together in a covalent bond

Question 16

A neutral group of atoms joined by covalent bonds

Answer 16

Molecule

Question 17

Double bond

Answer 17

When two atoms share two pairs of electrons

Question 18

Triple bond

Answer 18

When two atoms share three electrons

Question 19

Compound that is made up of molecules

Answer 19

Molecular compound

Question 20

Properties of molecular compounds

Answer 20

Poor conductivity, low melting point and boiling points

Question 21

Covalent bond in which electrons are shared equally

Answer 21

Non polar bond

Question 22

Covalent bond in which electrons are shared unequally

Answer 22

Polar bond

Question 23

How do you bonded Adams become partially charged

Answer 23

Having an equal sharing of electrons

Question 24

What is the structure of a metal crystal

Answer 24

Composed of closely packed positively charged metal ions

Question 25

An attraction between a positive metal ion and the electrons surrounding it

Answer 25

Metallic bond

Question 26

Properties of metals

Answer 26

Luster malleability ductility thermal conductivity and electrical conductivity

Question 27

A mixture made of two or more elements with at least one metal

Answer 27

Alloy

Question 28

How do you know that a chemical reaction has taken place

Answer 28

A new substance is formed

Question 29

Any change that alters the form or appearance of a substance but does not change it into another substance

Answer 29

Physical change

Question 30

A change in matter that produces one or more new substances

Answer 30

Chemical change

Question 31

Substances that undergo a chemical change

Answer 31

Reactant

Question 32

New substances that form from a chemical change

Answer 32

Products

Question 33

How do chemical changes occur

Answer 33

One existing bonds break and new bonds form

Question 34

How do you identify a chemical reaction

Answer 34

Changes in property and changes in energy that you can often observed

Question 35

How is mass conserved during a chemical reaction

Answer 35

All of the atoms present at the start of the reaction are present at the end

Question 36

Number placed in front of a chemical formula in an equation

Answer 36

Coefficient

Question 37

Minimum amount of energy needed to start a chemical reaction

Answer 37

Activation energy

Question 38

Increases the reaction rate by lowering the activation energy needed

Answer 38

Catalyst

Question 39

Biological catalyst in body that Help reactions occur at body temperature

Answer 39

Enzymes

Question 40

Material used to decrease the rate of a chemical reaction

Answer 40

Inhibitor

Question 41

What affects the rate of a chemical reaction

Answer 41

Surface area temperature concentration and presence of a catalyst and inhibitors

Question 42

When two or more elements or compounds combined to make a more complex substance

Answer 42

Synthesis reaction

Question 43

When compounds break down into simpler products

Answer 43

Decomposition reaction

Question 44

When one element replaces another element in a compound

Answer 44

Replacement reaction