Question

unit 2 – atoms and the periodic table – guided notes
2.1 atomic theory
summarize dalton’s atomic theory:
1.
2.
3.
4.
5.
summarize the law of definite proportions
summarize the law of multiple proportions
2.2 atomic structure and symbolism
define:
neutron
proton
electron
nucleus

Explanation:

Dalton's Atomic Theory Summary

1. All matter is made of indivisible atoms.
2. Atoms of the same element are identical in mass and properties.
3. Atoms of different elements have unique masses and properties.
4. Atoms combine in fixed whole-number ratios to form compounds.
5. Atoms are neither created nor destroyed in chemical reactions, only rearranged.

Law of Definite Proportions Summary

A chemical compound always contains the same elements in exactly the same proportion by mass, regardless of the sample size or source of the compound.

Law of Multiple Proportions Summary

When two elements form more than one compound, the masses of one element that combine with a fixed mass of the other element are in the ratio of small whole numbers.

Atomic Structure Definitions

• Neutron: A neutral (no charge) subatomic particle found in the atomic nucleus, with a mass approximately equal to that of a proton.
• Proton: A positively charged subatomic particle found in the atomic nucleus, which determines the element's atomic number.
• Electron: A negatively charged subatomic particle that orbits the atomic nucleus, with a much smaller mass than protons or neutrons.
• Nucleus: The dense, central core of an atom that contains protons and neutrons, accounting for nearly all of the atom's mass.

Answer:

Dalton's Atomic Theory

1. Matter is made of indivisible atoms.
2. Same-element atoms are identical.
3. Different elements have unique atoms.
4. Atoms combine in fixed whole-number ratios.
5. Atoms are conserved in chemical reactions.

Law of Definite Proportions

A compound has fixed element mass proportions, regardless of sample size/source.

Law of Multiple Proportions

For two elements forming multiple compounds, fixed mass ratios of elements are small whole numbers.

Atomic Structure Definitions

• Neutron: Neutral nucleus subatomic particle
• Proton: Positively charged nucleus subatomic particle
• Electron: Negatively charged subatomic particle orbiting the nucleus
• Nucleus: Dense central core of an atom holding protons and neutrons