10/16/2014 take our your worksheet from yesterday! complete your ws on determining the identity of...

10/16/2014

• Take our your worksheet from yesterday!

• Complete your WS on determining the identity of an element before your Bell Ringer.

• If you get finished, copy the Bell Ringer into your journal and answer the questions.

• TEST tomorrow so look over your notes NOW.

Thursday 10/16/2014 Bell Ringer:

Write and complete the statements.

1. The identity of an element is determined by _______________.

2. In a neutral atom, the # of protons equals the # of ____________.

3. The # of neutrons can change. Neutrons add ________ to the atom.

Thursday 10/16/2014 Bell Ringer:

Write and complete the statements.

1. The identity of an element is determined by # of protons in the nucleus. A=P

2. In a neutral atom, the # of protons equals the # of electrons. A=P=E

3. The # of neutrons can change. Neutrons add mass to the atom.

Elements are made of only 1 kind of atom, and the atom is identified by the # of protons in the nucleus.

Mass

• Mass is the amount of matter in something.

• The unit of measure for atoms is amu (atomic mass unit)

Atomic Mass Unit

1 atomic mass unit = 1.66053886 × 10-27 kg Kg is Kilograms

Relative Mass of Subatomic Particles

What is a Symbol?

Elements and Chemical Symbols

Chemical Symbols / Element Names

H

Hydro

gen

OOxygenCo

Cobalt

Cl

Chlor

ine

CCarbon

Writing Chemical Symbols

1. First letter is capitalized

2. Second letter is lower case

3. NO period at the end

H Cl O Hg Fe Sn C He

Co or CO

Does it really matter?

Co

Cobalt-60, extensively used as a tracer and a radiotherapeutic

http://members.tripod.com/duebills/27.html

Alloys for metals used in jet turbines

Co

CO

http://www.cpsc.gov/cpscpub/pubs/466.html

Kills 200 People

in United States

COProduced by IncompleteBurning of Fossil Fuels

carbon monoxide ColorlessOdorlessPoisonous gas

carbon oxygen

COCompound

Think beforeyou write aElement’sSymbol

Elements are substances:

•That cannot be broken down into other substances

•Made of atoms with the same number of protons in the nucleus

Elements are listed on thePeriod Table

Use your copy of the Periodic Table of Element

Correctly write the symbol for:

1.Carbon2.Nitrogen3.Oxygen4.Iron5.Chlorine

CNOFeCl

Atomic Number

Number of Protons in everyAtom of that Element

What is the name of the element with the following

number of protons?

A.2B.6C.8D.11E.47

Helium

Carbon OxygenSodiumSilver

Use th

e

Perio

dic T

able

Protons + electrical charge

NeutronNo electrical charge

Electrons- electrical charge

+

-

Neutral Atoms(Atoms without Electric Charge)

Have equal numbers of:

Protons (+ charges)

Electrons (- charges)

A=P=E

• Atomic # = # Protons = # Electrons

• Because the number of positive charges equals the number of negative charges, the atom is neutral (no charge)

How many electrons?

1 proton

9 protons

99 protons

1 electron

9 electrons

99 electrons

Atomic Mass

The atomic mass is listed on the individual element card on the Periodic Table.

Isotopes

• Not all atoms of the same element have the same number of neutrons. Most Carbon atoms have 6 neutrons, although some have more and some have less. Atoms of the same element with differing numbers of neutrons are called isotopes. The number of neutrons does not change the atom or the element it makes up; it just changes the mass of the atom. Most elements have isotopes.

Atomic Mass Number

Protons + Neutrons

1. Round the Mass Number to the nearest whole number

Round to 28

To calculate # of neutrons

Atomic Mass NumberProtons + Neutrons

2. Subtract Atomic NumberFrom Mass Number

28 (Mass #)

-14 (Atomic #) 14 Neutrons

Calculate # of neutrons

To find the AVERAGE # of Neutrons in the atom

• Round the atomic mass to a whole #

• Subtract the # of protons (also the atomic #)

• The difference is the average # of neutrons in the nucleus.

M – A = N

M is the Mass # (atomic mass)

A is the atomic # (# of protons)

N is the # of neutrons

Use the Periodic Table and Math Skills

to fill in the blanksSymbo

lAtomi

c #

Mass #

#Proton

s

#Neutron

s

#Electron

s

He 2 4 2

3 7 3

N 7 7

Symbol

Atomic #

Mass #

#Proton

s

#Neutron

s

#Electron

s

He 2 4 2 2 2

Li 3 7 3 4 3

N 7 14 7 7 7

# protons is the atomic #protons + neutrons = mass ##electrons = # protons

•Part 2

Compounds2 or More Elements

Chemically Combined

Oxygen

Hydrogen Hydrogen2-H: 1-O

Water

HH

O

Ratio 2:1

Formulas use element symbolswith subscript numbers

H2O

1 is notshown

Change the ratioChange the substance

2:2

H2O2

Subscript numbers

http://www.wonderquest.com/images/2003-08-08-peroxide.jpg

HydrogenPeroxide

No subscripts??

NaCl1Na 1Cl

How many elements?

Salt

2

Sugar

C6H12O6

How many elements?3

How many hydrogen atoms?12

√ Check yourunderstanding

Use your

Periodic

Table

1. The symbol for carbon is –

A Ca

B c

C CA

D C


A Ca Incorrect:Symbol for calcium

B c Incorrect: 1st letter is always

a capital


C CA Incorrect:C is carbonThere is no

element with the symbol A

D C

Correct:Capital C is the symbol for carbon

2. How many protons are in an atom of sodium?

A 11

B 12

C 23

D 34


A 11

B 12

Correct:atomic # is 11

Incorrect:12 is the number ofneutrons


C 23

D 34

Incorrect:23 is the mass number

Incorrect:No subatomic particle #is found by adding theatomic and mass numbers

3.How many neutrons are there,if the mass number is 1 andthe atomic number is 1?

A 3

B 2

C 1

D 0


A 3

B 2

Incorrect:There may be more or less neutrons than protons

Incorrect:No subatomic particle #is found by adding theatomic and mass numbers


C 1

D 0

Incorrect: There is 1 proton & 1 electron

Correct: 1-1 = 0

4.How many electrons are inan atom of Cl?

A 17

B 18

C 35

D 0


A 17

B 18

Correct: There are 17 + charges, so there are17 - charges

Incorrect:35-17 = number of neutrons


C 35

D 0

Incorrect:Mass # is the sum of protons & neutrons

Incorrect:All neutral atoms haveat least 1 electron

5.Which of the following isa formula?

A H

B O

C H2O

D h2o


A H

B O

Incorrect:Symbol for hydrogen

Incorrect:

Symbol for oxygen


C H2O

D h2o

Correct:There are 2Elements The ratio is 2:1

Incorrect:1st letter is a capital2 is not written as a subscript

6.How many elements are in baking soda, NaHCO3 ?

A 6

B 5

C 4

D 3

6.How many elements are in

baking soda, NaHCO3 ?A 6

B 5

Incorrect:There are 6 atoms

Incorrect:The lower case “a” is partof the symbol for sodium

6.How many elements are in baking soda,NaHCO3 ?

C 4

D 3

Correct:4 elements: sodium, hydrogen, carbon, oxygenIncorrect:

3 is the subscript for oxygen

GraphicsMicrosoft Clip ArtMicrosoft Office Online


http://www.cpsc.gov/cpscpub/pubs/466.html

agenthttp://members.tripod.com/duebills/27.html


http://www.tea.state.tx.us/student.assessment/taks/booklets/science/g8e.pdf

Isotopes

• Not all atoms of the same element have the same number of neutrons. Most Carbon atoms have 6 neutrons, although some have more and some have less. Atoms of the same element with differing numbers of neutrons are called isotopes. The number of neutrons does not change the atom or the element it makes up; it just changes the mass of the atom. Most elements have isotopes.

10/16/2014 take our your worksheet from yesterday! complete your ws on determining the identity of...

Documents

number of neutrons

followingnumber of protons

kind of atom

individual element card

bell ringer

differing numbers of

number of negative charges

number of positive charges