Unit 7 - Elements and Compounds
Transcript of Unit 7 - Elements and Compounds
WHAT%ARE%THE$ATOMS?%DEMOCRITUS’$ATOMIC$THEORY$$
! All$ma3er$consists$of$ATOMS$
! Atoms$are$indestruc?ble$
! Atoms$are$solid$and$invisible$
! Atoms$are$homogeneous$
! Atoms$differ$in$size,$shape,$
mass,$posi?on,$arrangement$DEMOCRITUS$460$BC$–$370$BC$
Greek$Philosopher$
ATOM%=%CAN%NOT%BE%DIVIDED%
PARTICLE(S)$$=$$ATOM(S)$Imagine%atoms%like%<ny%balls%or%circles%
WHAT%ARE%THE$ELEMENTS?%! A%substance%made%up%of%just%ONE$KIND$OF$ATOMS.%! Cannot%be%broken%down%into%simple%substances%by%a%physical%or%
chemical%process.%
! ELEMENTS$have$the$same$atomic$number.%! 118%elements%are%known%(%94%found%naturally%+%24%made%in%laboratory)%
! Are%represented%by%symbols.%
! A$GROUP$OF$ATOMS$joined$together$is$called$a$MOLECULE$
Helium$ Hydrogen$ Oxygen$
A$CHEMICAL%SYMBOL$FOR$EACH$ELEMENT!%
Sodium$ Element’s%%Name%
Element’s%%Symbol%
11$ Atomic%Number%
Na$%–{%from%La(n%‘natrium’%}%
ROWS%ARE%CALLED%–{%PERIODS$COLUMNS%ARE%CALLED%–{%GROUPS$
METALS%=%%LEFT$SIDE$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$$NON%METALS%=%%RIGHT$SIDE$
Sodium$ Name%
Symbol%
11$ Atomic%Number%
7th%SCIENCE%%%%%%TEACHER:%IRINA%RUIZ%FIGUEROA%%
STUDENT:%%……….…………………………….………%
Atomic$Number$ $Element’s$Symbol$ Element’s$Name$
Use%the%back%of%this%page%to%design%your%element’s%list%from%1%to%20.%
ELEMENTS%ON%EARTH%
Ques<ons%for%Homework%
1. What%are%the%atoms?%
2. How%many%elements%are%found%in%nature?%
3. Which%is%the%most$common$metal$found%in%Earth%crust?%4. Which%is%the%most%common%non_metal$found%in%the%Earth%crust?%5. Suggest%why%people%used%to%believe%that%water%was%an%element?%
6. Name%2%gases%that%are%found%in%air.%%
7. Is%AIR%an%element?%Explain%your%answer.%
8. Which%element%has%atoms%with%the%smallest%mass?%
9. Which%of%the%first%20%elements%has%atoms%with%the$greatest$mass?%
10. Give%the$names%(not%symbols)%of%two$elements$in%the%same%period%as%magnesium.%
11. %Give%the$symbols%(not%names)%of%two$elements$in%the%same%group%as%helium.$