Chemistry Test

How do you find the number of valence electrons from the periodic table?

Look at the column/group number

What’s the maximum number of electrons the s orbital can hold

2

What’s the maximum number of electrons the p orbital can hold

6

What’s the maximum number of electrons the d orbital can hold

10

What’s the maximum number of electrons the f orbital can hold

14

Who created the Greek model?

Democritus and Leucippus

Why did no one believe Democritus and Leucippus?

Plato disagreed with them, while being more famous.

Letter a of Dalton’s atomic theory?

Each element is composed of extremely small particles called atoms

What does “atomos” mean?

indivisible

When was Dalton’s atomic theory created

1803

Letter b of Dalton’s atomic theory?

All atoms of a given element are identical, but they differ from those of any other element.

Letter c of Dalton’s atomic theory?

Atoms are neither created nor destroyed in a chemical reaction.

Letter d of Dalton’s atomic theory?

A given compound always has the same relative number and kinds of atoms.

What did Dalton believe atoms looked like?

hard and round, like marbles or ball bearings

What did the cathode ray tube experiment discover?

electrons

Who discovered the electron?

J.J. Thomson

What was J.J. Thomson’s atomic model known as?

Plum Pudding/Raisin bread model

What did JJ Thomson’s model of the atom show?

Negative charges are evenly distributed throughout the positively charged interior.

When was the electron discovered?

1897

What does a cathode ray tube do?

Converts electrical signals into a visual display by firing and steering a beam of electrons onto a glowing phosphor screen.

Who created the Law of Conservation of Matter?

Antoine Lavoisier

What does the Law of Conservation of Matter say?

A chemical reaction neither creates nor destroys matter but the matter is conserved.

Who is Antoine Lavoisier known as?

The Father of Modern Chemistry

What does the Law of Constant Composition state?

A given compound always contains the same element in the same proportions by mass.

What’s an example of the Law of Constant Composition?

Water (always 2 parts Hydrogen, 1 part Oxygen)

What experiment did Ernest Rutherford conduct?

Alpha scattering (gold foil) experiment

According to Ernest Rutherford, where is an atom’s positive charge/most of its mass concentrated?

In the core, at the atom’s center

What is the core of the atom called?

The nucleus, where protons and neutrons are located.

True or false: around the Nucleus is mostly empty space

What is Ernest Rutherford credited as?

The father of nuclear physics

Who first proposed the theory of the nucleus?

Ernest Rutherford

What did the Gold foil experiment discover?

Most of an atom's mass is located in a dense region we now call the nucleus.

Who CONDUCTED the Gold Foil Experiment?

Hans Geigor and Ernest Marsden

Who refined Rutherford's discovery of the nucleus and proposed

atomic structure later on?

Niels Bohr in 1913

What is the modern atomic theory?

The electron cloud model

What does the electron cloud model display?

It is impossible to know exactly where an electron is at any given time, and the electrons’ position drawn as indistinct clouds around the nucleus.

Who contributed to the electron cloud model?

Erwin Schrodinger, Werner Heisenberg, Planck, and Louis De Brogile

What does the Bohr model of the atom describe?

electrons orbit around the nucleus, much like how the planets orbit around the sun.

Is it possible to define with absolute precision, at the same time, both the position and the momentum of an electron, according to the Heisenberg Uncertainty Principle?

Not possible

What are the only 2 we can know about electrons?

Their energy and where we are most likely to find them

What is the region of space where a particular electron may be found called?

Orbital

Define orbital

A bit of space where there is a 95% chance of finding that particular electron. If an electron is in a particular orbital, you know about its energy

Define electron configuration of an atom

form of notation which shows how the electrons are distributed among the various atomic orbital and energy levels

What does He represent in EC configuration?

The thing we are finding the electron configuration for

What does 1 represent in EC configuration?

The level

What does 2 represent in EC configuration?

the # of electrons the orbital can hold

What does s represent in EC configuration?

the orbital letter

What does the Aufbau principle state?

electrons fill orbitals starting at the lowest available (possible) energy levels before filling higher levels

What does Hund’s rule state?

The electrons fill the orbitals singly as far as possible before pairing can take place

What does Pauli’s exclusion principle state?

Only 2 electrons

with opposite spins can occupy an orbital

What is an easy way to calculate the number of orbitals found in an energy level?

n²

How do you know what level an element is in?

Look at the horizontal row (period) on the periodic table

What’s an easy way to calculate the number of electrons that can be held by a given energy level?

2n⁴, where n is the energy level #

Define atom

The smallest particle of an element that has all the properties of the element.

Z=

atomic number

A=

Mass number

How to find number of neutrons in an element?

Atomic number-mass number

Which group on the periodic table are noble gases

group 8A

What description best matches the Lewis Dot Diagram?

a simple drawing that shows the valence electrons (outermost electrons) of an atom and how they are shared or arranged in a molecule

How do you find the number of core electrons?

Total electrons - valence electrons