Exam (elaborations)
Atomic Theory Unit Questions and Answers 100% Solved
- Course
- Institution
Exam of 3 pages for the course Atom at Atom (Atomic Theory Unit)
[Show more]
Content preview
Atomic Theory UnitWhy were Democritus's idea rejected by other philosophers of the time? - answer
Democritus could not answer or explain what held atoms together as he did not know.
One said philosopher is Aristotle. He believed that instead of being matter being made
of tiny particles (atoms) that they were all fundamentally air, fire, water, and earth.
Which statements in Dalton's original atomic theory are now considered to be incorrect?
Describe how modern atomic theory differs from these statements? - answer The
indivisibility of an atom was proved wrong: an atom can be further subdivided into
protons, neutrons, and electrons. However, an atom is the smallest particle that takes
part in chemical reactions.
According to Dalton, the atoms of the same element are similar in all respects.
However, atoms of some elements vary in their masses and densities. These atoms of
different masses are called isotopes. For example, chlorine has two isotopes with mass
numbers 35 and 37.
Dalton also claimed that atoms of different elements are different in all respects. This
has been proven wrong in certain cases: argon and calcium atoms each have an atomic
mass of 40 amu. These atoms are known as isobars.
According to Dalton, atoms of different elements combine in simple whole number ratios
to form compounds. This is not observed in complex organic compounds like sugar
(C12H22O11).
The theory fails to explain the existence of allotropes; it does not account for differences
in properties of charcoal, graphite, diamond.
Democritus and Dalton both proposed the concept of atoms. Describe the method each
of them used to reach the conclusion that atoms existed. - answerDemocritus
developed his ideas about atoms
through intellectual thought, whereas Dalton
developed his ideas by performing experiments
and making careful measurements. Because
Democritus used only thought and not controlled
experiments, he had no observable facts to
support his ideas and no means of testing his
theories
Compare and contrast the atomic theories proposed by Democritus and John Dalton. -
answer
What particles are found in the nucleus of the atom? What is the charge of the nucleus?
Be able to draw and label an atom. - answerProtons and neutrons, a positive charge
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card or Stuvia-credit for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller julianah420. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for $12.99. You're not tied to anything after your purchase.
Can Stuvia be trusted?
4.6 stars on Google & Trustpilot (+1000 reviews)
83637 documents were sold in the last 30 days
Founded in 2010, the go-to place to buy study notes for 14 years now