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Explain Why blackboards are not scratched by chalk but by the sand embedded in the chalk?
Wiki User
∙ 9y ago
Blackboards are not scratched by chalk because chalk is softer than the material from which the blackboard is constructed. Sand scratches blackboards because it is harder than the material from which a blackboard is made.
Wiki User
∙ 9y ago
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What a piece of calcite is used to write or draw on blackboards?
It is chalk.
Why is chalk dissolving important?
so that people are able to efficiently clean blackboards and sidewalks where chalk has been used
What type of limestone is used in classrooms?
The sedimentary rock, chalk, a form of limestone, was used in the past as a writing instrument on slate blackboards, but most 'chalk' today is actually gypsum.
What are the raw materials in crayons?
Chalk, the stuff associated with blackboards, is made of gypsum. Gypsum is a naturally occurring mineral and is calcium sulfate. http://en.wikipedia.org/wiki/Chalk
Why might a long piece of chalk measure 8 units and3 units?
Measure the lenth of a long piece of chalk the chalk is 8units long it was 3 units long explain why both measurements might be corret
Explain why blackboards are not scratched by chalk but are scratched by the sand embedded in the chalk?
The hardness of sand is higher.
What do you use chalk for?
Writing on blackboards
How come ants cross chalk on blackboards?
hurry up and answer
What a piece of calcite is used to write or draw on blackboards?
It is chalk.
Why is chalk dissolving important?
so that people are able to efficiently clean blackboards and sidewalks where chalk has been used
What is the chalk that is used in blackboards chemically made up of?
Calcium Carbonate ( CaCO3)
What rock is a pure white form of this rock is used to write on blackboards?
Chalk.
How would chalk dissolving be important in the real world?
so that people are able to efficiently clean blackboards and sidewalks where chalk has been used
What type of limestone is used in classrooms?
The sedimentary rock, chalk, a form of limestone, was used in the past as a writing instrument on slate blackboards, but most 'chalk' today is actually gypsum.
Who invented white chalk?
WHITE Chalk isn't something that was invented. Chalk is a soft porous rock which is a form of limestone made up of the mineral calcite. Blackboards and blackboard chalks have been around since the late 1700's.
What are the raw materials in crayons?
Chalk, the stuff associated with blackboards, is made of gypsum. Gypsum is a naturally occurring mineral and is calcium sulfate. http://en.wikipedia.org/wiki/Chalk
Why don't we use black boards?
Chalk is used because it is cheap, it shows up well on blackboards and is easy to erase.
