PPT: Exploring Substances: Acidic, Basic, and Neutral | PPTs for Class 7 PDF Download

 Page 1


Exploring Substances: 
Acidic, Basic, and 
Neutral
Page 2


Exploring Substances: 
Acidic, Basic, and 
Neutral
Introduction
The Science Fair
On 28 February, the 
school celebrated 
National Science Day 
with a science fair.
The Magic Paper
A volunteer sprayed 
liquid on blank sheets, 
revealing hidden 
words that amazed 
Ashwin and Keerthi.
Colorful Chemistry
At the Colourful World of Substances stall, they 
witnessed experiments where mixing substances 
changed colors.
Page 3


Exploring Substances: 
Acidic, Basic, and 
Neutral
Introduction
The Science Fair
On 28 February, the 
school celebrated 
National Science Day 
with a science fair.
The Magic Paper
A volunteer sprayed 
liquid on blank sheets, 
revealing hidden 
words that amazed 
Ashwin and Keerthi.
Colorful Chemistry
At the Colourful World of Substances stall, they 
witnessed experiments where mixing substances 
changed colors.
Nature - Our Science Laboratory
Indicators
Special tools that change 
color or smell when 
mixed with different 
substances.
Natural Sources
Many indicators come 
from plants and other 
natural materials.
Classification
Help us determine if 
substances are acidic, 
basic, or neutral.
Page 4


Exploring Substances: 
Acidic, Basic, and 
Neutral
Introduction
The Science Fair
On 28 February, the 
school celebrated 
National Science Day 
with a science fair.
The Magic Paper
A volunteer sprayed 
liquid on blank sheets, 
revealing hidden 
words that amazed 
Ashwin and Keerthi.
Colorful Chemistry
At the Colourful World of Substances stall, they 
witnessed experiments where mixing substances 
changed colors.
Nature - Our Science Laboratory
Indicators
Special tools that change 
color or smell when 
mixed with different 
substances.
Natural Sources
Many indicators come 
from plants and other 
natural materials.
Classification
Help us determine if 
substances are acidic, 
basic, or neutral.
Litmus as an Indicator
What is Litmus?
A natural material from 
lichens - organisms formed 
by fungi and algae living 
together on rocks and trees.
How It Works
Blue litmus turns red in 
acids
Red litmus turns blue in 
bases
No change in neutral 
substances
Tested Substances
Acids: Lemon juice, 
vinegar
Bases: Soap, baking 
soda
Neutral: Water, sugar 
solution
Page 5


Exploring Substances: 
Acidic, Basic, and 
Neutral
Introduction
The Science Fair
On 28 February, the 
school celebrated 
National Science Day 
with a science fair.
The Magic Paper
A volunteer sprayed 
liquid on blank sheets, 
revealing hidden 
words that amazed 
Ashwin and Keerthi.
Colorful Chemistry
At the Colourful World of Substances stall, they 
witnessed experiments where mixing substances 
changed colors.
Nature - Our Science Laboratory
Indicators
Special tools that change 
color or smell when 
mixed with different 
substances.
Natural Sources
Many indicators come 
from plants and other 
natural materials.
Classification
Help us determine if 
substances are acidic, 
basic, or neutral.
Litmus as an Indicator
What is Litmus?
A natural material from 
lichens - organisms formed 
by fungi and algae living 
together on rocks and trees.
How It Works
Blue litmus turns red in 
acids
Red litmus turns blue in 
bases
No change in neutral 
substances
Tested Substances
Acids: Lemon juice, 
vinegar
Bases: Soap, baking 
soda
Neutral: Water, sugar 
solution
Red Rose as an Indicator
Preparation
Fresh rose petals are crushed 
and soaked in hot water, then 
filtered to get a red-colored 
liquid.
Acidic Reaction
In acidic substances like 
lemon juice, the extract 
changes to a shade of red.
Basic Reaction
In basic substances like soap 
solution, the extract changes 
to a shade of green.