week 1, concept 3 : Dalton's atomic theory & structure of the atom (matter and atoms)

Question 1

Answer 1

concept 3 :

Dalton’s atomic theory and

structure of the atom

Question 2

Answer 2

chapter 2

atoms

Question 3

etymology-

the word atom comes from _ and means _

Answer 3

• Greek word atomos
• ‘indivisible’ based on ‘not to cut’

Question 4

democritus hypothesised in around 400bc and believed that-

all matter is made of _ which are much _, and he called these _.

Answer 4

• very small particals
• to small to see
• atoms

Question 5

All atoms of the _ element have the same chemical properties.

Atoms of _ elements have different chemical properties.

Answer 5

_same

_different

Question 6

Compounds are formed by the chemical combination of _ different kinds of atoms.

Answer 6

Compounds are formed by the chemical combination of 2 or more different kinds of atoms.

Question 7

A molecule is a _ combination of two or more atoms that acts as a_.

Answer 7

_tightly bound

_single unit

Question 8

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.

Answer 8

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.

Question 9

visual example of law of conservation on mass

Answer 9

Question 10

One amu is defined as _ the mass of a _ atom with _ protons and _ neutrons

Answer 10

One amu is defined as 1/12 the mass of a carbon atom with 6 protons and 6 neutrons

Question 11

Question 12

* all compounds are molecules, but _

Answer 12

not all molecules are compounds.

Question 13

subatomic particle:

Answer 13

• any of numerous subatomic constituents of the physical world that interact with each other, including electrons, neutrinos, photons, and alpha particles
• proton (+)
• neuton (-)

Question 14

positive charge and negative charge causes _ that pulls them together

Answer 14

positive charge and negative charge causes attraction that pulls them together

Question 16

electron cloud:

Answer 16

the region around a nucleus

Question 17

the number of protons is always equal to the number of _ in an element

Answer 17

the number of protons is always equal to the number of electrons in an element

Question 18

_ element is used as a reference for mass unit

Answer 18

carbon element is used as a reference for mass unit

Question 19

to work out the atomic mass unit (amu) every single element is compared to _

Answer 19

carbon

Question 20

AMU:

Answer 20

atomic mass unit

Question 21

Atomic number:

Answer 21

number of protons

Question 22

atomic mass number (amu):

Answer 22

the number of protons and neutrons

Question 23

isotopes:

Answer 23

forms of the same element with different number of neutrons