Dalton's atomic theory (article) | Khan Academy (2024)

The postulates of Dalton's atomic theory: which points do we still use today, and what have we learned since Dalton?

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  • garrettjmoore14

    9 years agoPosted 9 years ago. Direct link to garrettjmoore14's post “Why is Daltons theory sti...”

    Why is Daltons theory still taught if it is not 100% accurate?

    (281 votes)

    • yuki

      9 years agoPosted 9 years ago. Direct link to yuki's post “It is also helpful to thi...”

      Dalton's atomic theory (article) | Khan Academy (4)

      Dalton's atomic theory (article) | Khan Academy (5)

      Dalton's atomic theory (article) | Khan Academy (6)

      It is also helpful to think about how science is always evolving-we are always learning new things and modifying existing theories to take into account new discoveries. That happened to Dalton's atomic theory, and that will likely to happen to many more theories to come!

      (407 votes)

  • Hridanshu Ruparel

    9 years agoPosted 9 years ago. Direct link to Hridanshu Ruparel's post “Why is not possible to fu...”

    Why is not possible to further separate atoms??

    (42 votes)

    • Esther Dickey

      9 years agoPosted 9 years ago. Direct link to Esther Dickey's post “Actually, it is. Atoms a...”

      Dalton's atomic theory (article) | Khan Academy (10)

      Dalton's atomic theory (article) | Khan Academy (11)

      Dalton's atomic theory (article) | Khan Academy (12)

      Actually, it is. Atoms are made up of protons, neutrons, and electrons. However, if you remove any of these particles the atom will have different properties. An atom is the smallest particle of an element that has all the properties of the element. For example, sodium in its pure form reacts violently with water. When you take away one of its electrons, it becomes part of table salt and no longer reacts with water.

      (150 votes)

  • Eryquin-Mor

    9 years agoPosted 9 years ago. Direct link to Eryquin-Mor's post “In part 3 of the article,...”

    In part 3 of the article,(Compounds are combinations of 2 or more different atoms) how is it possible that we don't get affected by the different properties of the elements and get sick if chlorine is a TOXIC gas and sodium is a highly REACTIVE metal?

    (21 votes)

    • Matt B

      9 years agoPosted 9 years ago. Direct link to Matt B's post “Sodium and chlorine are t...”

      Dalton's atomic theory (article) | Khan Academy (16)

      Dalton's atomic theory (article) | Khan Academy (17)

      Dalton's atomic theory (article) | Khan Academy (18)

      Sodium and chlorine are toxic/explosive because they are unstable and therefore very reactive. If you look at the electrons in the shells, they want to react to fill their outer shell of electrons. Once they react, they exist as ions and then lose their property of being super-reactive because they then become stable.

      (59 votes)

  • Danny

    8 years agoPosted 8 years ago. Direct link to Danny's post “Why can't there be half a...”

    Why can't there be half an atom? And why are chemists so sure?

    (18 votes)

    • brettjsnyder

      8 years agoPosted 8 years ago. Direct link to brettjsnyder's post “We say that an atom can't...”

      Dalton's atomic theory (article) | Khan Academy (22)

      Dalton's atomic theory (article) | Khan Academy (23)

      Dalton's atomic theory (article) | Khan Academy (24)

      We say that an atom can't be cut in half, not because it can't actually be split (aka nuclear fission - reactor, bomb) but rather because the resulting parts would no longer be atoms the elements the you started with. Ex: you can't split a Helium atom because to do so would result in 1 or 2 Hydrogen atoms and some leftover bits - but it would no longer BE Helium.

      (66 votes)

  • Pooja Goyal

    8 years agoPosted 8 years ago. Direct link to Pooja Goyal's post “cant we put protons (h+) ...”

    cant we put protons (h+) into a nucleus of he (he+) to get nucleus of an new element

    (9 votes)

    • sedspqr

      8 years agoPosted 8 years ago. Direct link to sedspqr's post “To do this would require ...”

      Dalton's atomic theory (article) | Khan Academy (28)

      To do this would require nuclear fusion (combining smaller atomic nuclei to form a larger one), a process which is not yet quite possible in the lab. It would produce more energy than an atomic bomb would.
      It is not nonexistent, however. This process occurs constantly in the core of the sun - basically, what you asked about is what gives Earth the energy necessary to support human life!

      (18 votes)

  • Thadd Hudson

    9 years agoPosted 9 years ago. Direct link to Thadd Hudson's post “Did Dalton make up anothe...”

    Did Dalton make up another theory that we can use instead of the one that was originally created?

    (7 votes)

    • Elijah Sy

      9 years agoPosted 9 years ago. Direct link to Elijah Sy's post “Well there are several pa...”

      Dalton's atomic theory (article) | Khan Academy (32)

      Well there are several parts to Dalton's theory. His only theory is the atomic theory and today we know that atoms can be destroyed by nuclear reactions but not by chemical reactions. Also, there are different kinds of atoms (differing by their masses) within an element that are known as "isotopes", but isotopes of an element have the same chemical properties. Hope that helped. But his theory was not 100% correct.

      -http://www.iun.edu/~cpanhd/C101webnotes/composition/dalton.html

      (11 votes)

  • Sam D

    9 years agoPosted 9 years ago. Direct link to Sam D's post “Didn't Antoine Lavoisier ...”

    Didn't Antoine Lavoisier propose the law of conservation of mass?

    (8 votes)

    • Matt B

      9 years agoPosted 9 years ago. Direct link to Matt B's post “A peer reviewed journal, ...”

      A peer reviewed journal, ERIC, published "A Historical Note on the Conservation of Mass." This states in their abstract that this is not entirely true:

      "Although most historians of science attribute the formulation of the law of conservation of matter in chemical reactions to Antoine Lavoisier at the end of the eighteenth century, several earlier researchers had already assumed this law in their work. These researchers include Joseph Black, Henry Cavendish, M. V. Lomonosov, and Jean Rey."

      (9 votes)

  • Vijeya Patel

    9 years agoPosted 9 years ago. Direct link to Vijeya Patel's post “well as far as I understa...”

    well as far as I understand this concept,atoms cannot bee further divided but we know that atoms are further divided into fundamental particles as protons,electrons and neutrons.So why does this conclusion given by dalton sir still hold true??

    (7 votes)

    • Ernest Zinck

      9 years agoPosted 9 years ago. Direct link to Ernest Zinck's post “Many of Dalton's original...”

      Many of Dalton's original postulates of an atomic theory have had to be modified in the light of later discoveries.
      As far as chemical reactions go, the essential concept that chemical reactions involve atoms and molecules still remains.
      In many other cases, chemists have to use the concept of electrons, protons, etc.
      Dalton's atomic formed the basis of chemistry, but modern chemists have long since adapted their understanding to include later discoveries.

      (8 votes)

  • Erin Boyle

    8 years agoPosted 8 years ago. Direct link to Erin Boyle's post “Why can you not add proto...”

    Why can you not add protons/neutrons/electrons to an atom?

    (2 votes)

    • Matt B

      8 years agoPosted 8 years ago. Direct link to Matt B's post “You cannot add protons an...”

      Dalton's atomic theory (article) | Khan Academy (42)

      You cannot add protons and neutrons because they are in the center of an atom and held tighly by the strong nuclear force. However, you can add electrons to atoms and this happens all the time: the gaining and losing of electrons is precisely what chemical reactions are!

      (13 votes)

  • Rohan Jaswal

    8 years agoPosted 8 years ago. Direct link to Rohan Jaswal's post “What is the difference be...”

    What is the difference between an element and molecule?

    (4 votes)

    • Abdülrezzak Bostani

      8 years agoPosted 8 years ago. Direct link to Abdülrezzak Bostani's post “in summary:element - a b...”

      in summary:
      element - a basic substance that can't be simplified (hydrogen, oxygen, gold, etc...)
      atom - the smallest amount of an element
      molecule - two or more atoms that are chemically joined together (H2, O2, H2O, etc...)
      compound - a molecule that contains more than one element (H2O, C6H12O6, etc...)

      (4 votes)

Dalton's atomic theory (article) | Khan Academy (2024)

FAQs

What was Dalton's atomic theory very short answer? ›

(1) Elements consist of indivisible small particles (atoms). (2) All atoms of the same element are identical; different elements have different types of atom. (3) Atoms can neither be created nor destroyed.

What was Dalton's atomic theory successfully explained? ›

Dalton based his theory on the law of conservation of mass and the law of constant composition. The first part of his theory states that all matter is made of atoms, which are indivisible. The second part of the theory says all atoms of a given element are identical in mass and properties.

How can you summarize Dalton's atomic theory? ›

Dalton's Atomic Theory (1804)

The general tenets of this theory are as follows: All matter is composed of extremely small particles called atoms. Atoms of a given element are identical in size, mass, and other properties. Atoms of different elements differ in size, mass, and other properties.

What are 5 postulates of Dalton's atomic theory? ›

All matter consists of indivisible particles called atoms. Atoms of the same element are similar in shape and mass, but differ from the atoms of other elements. Atoms cannot be created or destroyed. Atoms of different elements may combine with each other in a fixed, simple, whole number ratios to form compound atoms.

What are the 5 statements of Dalton's theory? ›

Dalton proposed a new theory of the atom, known as Dalton's atomic theory, which includes the tenets that all matter is composed of atoms, atoms of a given element are identical in size and mass, atoms cannot be subdivided, created or destroyed, atoms of different elements can combine in simple whole number ratios to ...

How was Dalton's theory proven? ›

In 1803 Dalton discovered that oxygen combined with either one or two volumes of nitric oxide in closed vessels over water and this pioneering observation of integral multiple proportions provided important experimental evidence for his incipient atomic ideas.

What was the one important change to Dalton's theory? ›

Explanation: Thomson's experiments with cathode ray tubes helped him to discover the electron (which Dalton did not know about). Dalton thought that atoms were indivisible particles, and Thomson's discovery of the electron proved the existence of subatomic particles.

Why is the atomic theory important? ›

The atomic theory is important because it describes the composition of the atom and the properties of the subatomic particles as well as their behavior. Matter is composed of atoms, and it is important to know information about quantum chemistry.

What is a good description of Dalton's model of an atom? ›

It is often referred to as the billiard ball model. He defined an atom to be a ball-like structure, as the concepts of atomic nucleus and electrons were unknown at the time. If you asked Dalton to draw the diagram of an atom, he would've simply drawn a circle!

What is the concept of the atomic theory? ›

atomic theory, ancient philosophical speculation that all things can be accounted for by innumerable combinations of hard, small, indivisible particles (called atoms) of various sizes but of the same basic material; or the modern scientific theory of matter according to which the chemical elements that combine to form ...

Is Dalton's atomic theory correct? ›

Although Dalton didn't get it completely correct, his theory set the foundation for today's atomic model. His theory incorporated both the law of conservation of mass and constant composition. He also developed the law of multiple proportions.

Which parts of Dalton's atomic theory are true? ›

Although two centuries old, Dalton's atomic theory remains valid in modern chemical thought. 1) All matter is made of atoms. Atoms are indivisible and indestructible. 3) Compounds are formed by a combination of two or more different kinds of atoms.

Can atoms be created or destroyed? ›

The atom itself is neither created nor destroyed but cycles among chemical compounds. Ecologists can apply the law of conservation of mass to the analysis of elemental cycles by conducting a mass balance.

What is the atomic theory for kids? ›

The atom is the basic building block for all matter in the universe. Atoms are extremely small and are made up of a few even smaller particles. The basic particles that make up an atom are electrons, protons, and neutrons. Atoms fit together with other atoms to make up matter.

What is Dalton's atomic theory quizlet? ›

Dalton's atomic theory states that all elements are made of atoms For any one element, all the atoms are the same. Different elements are made from different kinds of atoms. Atoms from different elements can combine to make compounds,. Each compound always has the same relative numbers and kinds of atoms.

What was Dalton's atomic theory grade 8? ›

Postulates of Dalton's Atomic Theory

All atoms of a specific element are identical in mass, size, and other properties. However, atoms of different element exhibit different properties and vary in mass and size. Atoms can neither be created nor destroyed. Furthermore, atoms cannot be divided into smaller particles.

Which of the following is explained by Dalton's atomic theory? ›

Hence, Dalton's atomic theory successfully explained the Law of conservation of mass, the Law of constant composition, and the Law of multiple proportions i.e Option(D): ( i ) , ( ii ) and ( iv ) .

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