chem ch 4

________- the particles that determine the identity of an element.

________- the particles that determine the identity of an element.

Protons

Negative charge, -1 g (amu), outside the nucleus.

Electrons

________= discovered the nucleus; did the gold leaf expierement

Rutherford

Individual building blocks of matter; pieces of elements from the table.

Atoms

• the particles found in the nucleus.

Protons and neutrons

Anything made up of at least 2 non- metal atoms; can either be the same element.

Molecules

Proposed atoms are made of earth

Greeks

Worked with cathode ray and discovered that the rays are deflected by electric and magnetic fields

Jj thomson

Discovered the neutron

Chadwick

Identified the electron

Jj thomson

positive charge, 1+ g (amu), inside the nucleus

Protons

neutral charge, 0g (amu), inside the nucleus

Neutrons

Protons + neutrons

mass number

Protons + electrons

Net force/charge

Which particles affect the charge of an atom or ion

Electrons

Element symbol

What is normally in place of A

Net force/charge

What is normally in place of b

atomic number

what is normally in place of c

Atomic mass

What is normally in place of d

3

What is the atomic mass

2

What is the atomic number

+1

What is the charge

1

How many neutrons are there

2

How many protons are there

1

How many electrons are there

What two things must be true for an element to be an isotope

Diff number of neutrons/mass and the same number of protons/same element

An atom or molecule that gained or lost electrons

Ion

a positively charged ion; an ion that has lost electrons

cation

a negatively charged ion; an ion that has gained electrons

anion

What are the two forces that work in the nucleus

Strong nuclear force and electromagnetic repulsion

How do u calculate molar mass

Add together the molar mass from each individual atom in the compound (found on periodic table)

What are the units for molar mass

G/mol

What is the formula for calculating AAM

AAM= A(%A)+ B(%B) +…

In what order do u convert mass to atoms (mmpa)

Mass, mols, particles, atoms

What are the units for average atomic mass

amu

How do all atoms of the same element react

Chemically the same

proposed that atoms weren’t indivisible, but made up of smaller partciles called subatomic particles (proton, neutron, electron)

thomson

what did dalton’s atomic theory state and how does it relate to modern science

1. states all matter is made of tiny indivisible particles called atoms (proven wrong) ◦ modern science: atoms are not indivisble

2. atoms of the same element are exactly alike + have same mass; atoms of different elements have different masses ◦ modern science: concept of isotopes —> not quite right

3. in chemical reactions, atoms are combined, separated, or rearranged

4. atoms of diff elements combine in whole-number ratios to form chemical compounds

who developed the law of multiple proportions which states that when elements form compounds, the proportions of the elements in those chemical compounds can be expresses in small whole number rations (elements on the periodic table)

dalton

conducted experiments to determine the charge-to-mass ratio and the mass of the electron

milikan

found out that the electron is 9.109x10^-31kg

milikan

◦ found out that all atoms are able to produce electrons and atoms are not indivisble

milikan

determined the magnitude of electron charge

milikan

found that most alpha particles passed through, some angled slightly, and a tiny fraction bounced back

rutherford

found out that atom is mostly empty space, (+) particles are concentrated at the center of the nucleus (little nut), and that (-) particles orbit the nucleus

rutherford

who found out the purpose of the neutrons

chadwick

what is the purpose of neutrons

to stabalize the nucleus

◦ danish physicist proposed a model of the atom in which the electrons orbit the nucleus without losing energy ◦ calls each possible orbit a quantom ◦ based his theory on the work of planck ◦ proposed that light is made up of units of energy of a definite amount, each of which is called a energy level

bohr

a group of elements that have the same amount of protons but different masses/# of neutrons

isotopes

what is the difference between atoms and molecules

atoms are singular neutral particles molecules are bonded neutral atoms (2 or more atoms)