Quiz 1

Question 1

The atomic theory

Answer 1

1- Elements are composed of extremely small particles called atoms 

Question 2

The atomic theory

Answer 2

All atoms of one element are identical, have the same size, mass and chemical properties 

Question 3

The atomic theory

Answer 3

Compounds are composed of atoms of more than one element

Question 4

The atomic theory

Answer 4

A chemical reaction involves only the separation combination or rearrangements of atoms. It does not result in their creation or destruction (law of conservation of mass)

Question 5

Compounds

Answer 5

The same element can make different compounds differ in their number of atoms of each kind of that combine

Question 6

The structure of the atom

Answer 6

Atoms are made of small particles called subatomic particles ; electrons, protons, and neutrons

Question 7

Electron location

Answer 7

Outside the nucleus

Question 8

Proton and neutron location

Answer 8

Inside the nucleus

Question 9

The atomic number ( Z )

Answer 9

The number of protons in the nucleus of each atom of an element

Question 10

The atomic number ( Z )

Answer 10

Atoms can be identified by the number of protons and neutrons, they contain

Question 11

The atomic number ( Z )

Answer 11

The chemical identity of an atom can be determined from its atomic number 

Question 12

The mass number ( A )

Answer 12

The total number of neutrons and protons present in the nucleus of an atom of an element 

Question 13

The mass number ( A )

Answer 13

All atom nuclear contain both protons and neutrons. except for hydrogen, which has one proton and no neutrons 

Question 14

Nucleons

Answer 14

Protons and neutrons are called nucleons

Question 15

Neutron No.

Answer 15

The number of neutrons in an atom is equal to the difference between the mass number and the atomic number or ( A - Z )

Question 16

Isotopes

Answer 16

Atoms that have the same atomic number, but different mass numbers due to the difference in neutron number 

Question 17

Periodic table

Answer 17

A chart in which elements having similar chemical and physical properties are grouped together

Question 18

Periodic table

Answer 18

Elements are arranged by atomic number in horizontal rows called periods and in vertical columns known as groups or families 

Question 19

Periodic table

Answer 19

Elements are divided into three categories; metals, nonmetals and metalloids

Question 20

Metal elements

Answer 20

A metal is a good conductor of heat and electricity 

Question 21

none metal elements

Answer 21

Nonmetal is a poor conductor of heat and electricity

Question 22

Metalloids

Answer 22

A metalloid has properties that are intermediate between those of metals and nonmetals

Question 23

Groups special names

Answer 23

Group 1A elements are called alkali metals
Group 2A elements are called alkaline earth metals
Group 7A elements are called halogens
Group 8A elements are called noble gases or rare gases

Question 24

Molecules

Answer 24

An aggregate of at least two atoms in a definite arrangement held together by chemical forces 

Question 25

Compounds

Answer 25

Is made up of two or more elements. Thus, all compounds are molecules, but not all molecules are compounds 

Question 26

Diatomic molecules

Answer 26

Molecules that contain only two atoms. it can be two atoms of the same element or two atoms of different elements  H2 - HCl

Question 27

Polyatomic molecules

Answer 27

Molecules that contains more than two atoms, they can be atoms of the same element or a combination of two or more different elements  O3 - NH3

Question 28

Homonuclear molecules

Answer 28

Molecule is composed of only one type of elements O3 - H2

Question 29

Heteronuclear molecules

Answer 29

Molecules composed of more than one type of elements HCl - CO2

Question 30

Ions

Answer 30

An atom or a group of atoms that has a net positive or negative charge

Question 31

Cation

Answer 31

The loss of one or more electrons from a neutral atom 

Question 32

Anion

Answer 32

The gain of one or more electrons from a neutral atom 

Question 33

Monatomic ions

Answer 33

Single atoms that gain or lose more than one electron

Question 34

Ions

Answer 34

Metals tend to form cations and nonmetals form anions

Question 35

Polyatomic ions 

Answer 35

Ammonium NH4+ Carbonate CO3 ^2 - Cyanide CN- Nitrate NO3- Hydroxide OH- Permanganate MnO4 - Phosphate PO4 ^3- Sulphate SO4 ^2-

Question 36

Molecular formula

Answer 36

A Formula which shows the exact number of atoms of each element in the smallest unit of a substance. It tells the actual number of atoms in a molecule 

Question 37

Structural formula

Answer 37

Shows how atoms are bonded to one another in a molecule H — O — H

Question 38

Empirical formulas

Answer 38

The simplest chemical formulas they are written by reducing the subscript in the molecular formulas to the smallest possible number  Molecular formula : H2O2 Empirical formula : HO

Question 39

ionic compounds

Answer 39

Chemical compounds composed of ions held together by electrostatic forces called ionic bonding. The compound overall is neutral, but consist of cations and anions. 

Question 40

Atomic mass

Answer 40

The mass of an atom depends on the number of electrons, protons and neutrons it contains

Question 41

Atomic mass

Answer 41

The mass of the atom in atomic mass units

Question 42

Mole

Answer 42

The amount of a substance that contains Avogadro’s number of entities

Question 43

Avogadro’s number

Answer 43

NA = 6.022*10^23

Question 44

Molar mass 

Answer 44

Molar mass = (atomic mass of atom X * number of atom X ) + ( atomic mass of atom Y * number of atom Y ) + … unit ( g/mol )

Question 45

Number of moles

Answer 45

Number of moles equals mass in grams divided by molar mass n = m / M

Question 46

Number of particles

Answer 46

Number of particles equals Avogadro’s number times number of moles N = NA * n

Question 47

The percent composition by mass

Answer 47

The percent by mass of each element in a compound

Question 48

Percent composition

Answer 48

Percent composition of an element equals number of Mars times molar mass of element divided by molar mass of compound times 100 Present composition = ( n * molar mass of element / molar mass of compound )* 100