week 1, concept 3 : Dalton's atomic theory & structure of the atom (matter and atoms) Flashcards
concept 3 :
Dalton’s atomic theory and
structure of the atom
chapter 2
atoms
etymology-
the word atom comes from _ and means _
- Greek word atomos
- ‘indivisible’ based on ‘not to cut’
democritus hypothesised in around 400bc and believed that-
all matter is made of _ which are much _, and he called these _.
- very small particals
- to small to see
- atoms
All atoms of the _ element have the same chemical properties.
Atoms of _ elements have different chemical properties.
_same
_different
Compounds are formed by the chemical combination of _ different kinds of atoms.
Compounds are formed by the chemical combination of 2 or more different kinds of atoms.
A molecule is a _ combination of two or more atoms that acts as a_.
_tightly bound
_single unit
Law of Conservation of Mass
Matter can be neither _ nor _.
As Dalton explained, if matter is made up of _atoms, then any chemical reaction just changes the _ among atoms, but does not _ the atoms themselves.
Matter can be neither created nor destroyed.
As Dalton explained, if matter is made up of indestructable atoms, then any chemical reaction just changes the attachments among atoms, but does not destroy the atoms themselves.
visual example of law of conservation on mass
One amu is defined as _ the mass of a _ atom with _ protons and _ neutrons
One amu is defined as 1/12 the mass of a carbon atom with 6 protons and 6 neutrons
* all compounds are molecules, but _
not all molecules are compounds.
subatomic particle:
- any of numerous subatomic constituents of the physical world that interact with each other, including electrons, neutrinos, photons, and alpha particles
- proton (+)
- neuton (-)
positive charge and negative charge causes _ that pulls them together
positive charge and negative charge causes attraction that pulls them together
