Science Lesson 2 - The Periodic Table

Who created the first periodic table in 1869?

Mendeleev

Most elements, but not all, end in what 3 letters?

ium

Which of these statements is false? A. Technology speeds up element discovery. B. There are 22 groups on the periodic table. C. Particle accelerators are used to synthesize elements. D. The discovery of the first noble gas prompted the discovery of the others.

B There are 18 groups

Alkali Metals Lithium, sodium, and potassium are never found pure in nature. In fact, even in the lab these elements are normally stored in sealed glass jars under kerosene. 1. Why are alkali metals stored in kerosene? Select an answer. A. To make them solid. B. They are expensive. C. To stop them reacting with air. D. To make them shiny.

C

As of the end of 2016, 118 elements had been discovered. Which of these statements about the theoretical element 119 is most likely true? Select an answer. A. It will start a new group. B. It will be a noble gas. C. It will start a new period. D. It will be a non-metal.

C - It will start a new period

How was the periodic table developed?

Mendeleev produced a periodic table based on atomic weights but arranged 'periodically'.

The noble gases in Group 18 were some of the last natural elements to be discovered. Why do you think this is so?

Scientists discovered most elements because they reacted with other elements. Because the noble gases are extremely unreactive, they were not discovered until later.

What makes up most of the elements in the periodic table?

metals

Group 3-12 Iron, Copper, Nickel, Gold, Silver hard, shiny metals with high melting points good conductors of heat and electric current

transition metals

Fluorine, Chlorine, Bromine, Iodine

Halogens

Recall that the periodic table is organized by _______ number and also in groups by ______________.

atomic properties

Elements are grouped together in vertical columns according to similarities in their _________ and ___________ properties.

physical and chemical

a drawing or image of an actual thing

representation

About how many known elements are there?

100

There are 18 columns in the table, and so there are ____ groups.

18

The modern periodic table has ______ periods, each of which follows a pattern.

7

How many periods are on the periodic table?

8

Gold, silver, and platinum are highly valuable metals because of their similar chemical properties, such as low reactivity, high ductility, and high luster. Which of the following is another example of a precious metal, based on its location on the Periodic Table? A. palladium B. ytterbium C. oxygen D. nitrogen

A

Neon lights are commonly used in signs because they emit attractive colors of lights. Orange neon lights are filled with neon gas. Different gases produce different colors. 2. Which of these elements would you least expect to find in a neon light? 2. Which of these elements would you least expect to find in a neon light? A. argon B. chlorine C. krypton D. xenon

B Chlorine is a halogen gas All the others are nobel gasses

Assume that one particular atom of rhodium (Rh) has a mass of 102. Why does this number not exactly match the atomic mass of 102.91 listed on the periodic table for this element?

Because rhodium's atomic mass is a weighted average of all of the isotopes of that element Atoms of the same element can have different number of neutrons. These are called isotopes.

What information about elements is provided by the periodic table?

Chemical symbol atomic number atomic mass

What element is found in Group 6 and Period 4? Based on its location, is this element more similar to tungsten or to iron? Explain.

Chromium (Cr) Tungsten because elements in the same groups have similar properties.

Super strong magnets are typically made from neodymium, a rare earth metal. Rare earth metals are found together in Earth's crust. Which of the following is an example of an element that you'd need to separate from neodymium? A. nitrogen B. oxygen C. palladium D. ytterbium

D

How is the modern periodic table different from Mendeleev's periodic table?

The Mendeleev's periodic table is arranged in order by increasing atomic mass. The modern periodic table is arranged in order by increasing atomic number.

True or False - In his periodic table, Mendeleev left blank spaces because he predicted that the blank spaces would be filled by elements that had not yet been discovered.

True

____________ metals are so reactive that they are never found as free elements in nature. They are only found in compounds. They are shiny and so soft you can cut them with a plastic knife!!! These are in Group 1

alkali metals

Average mass of all the isotopes of an element

atomic mass

Mendeleev noticed that a pattern of properties appeared when he arranged the elements in order of increasing ____________ __________.

atomic mass

scientists use _______ ______ _________ (amu) to determine the mass of an element.

atomic mass units

The modern periodic table is arranged by increasing _______ number.

atomic number (the number of protons in an atom's nucleus)

How is the table arranged now? Why did it change?

by increasing atomic mass because we now know that the number of protons is related to the chemical properties of an element

a one- or two- letter abbreviation for an element

chemical symbol

melting point boiling point density appearance state at room temperature

examples of physical properties of elements

elements in the same vertical column of the periodic table; also called a family

group

In the periodic table, the vertical columns are called _________ and these elements have similar properties with each other.

groups another name is families

_____________ are the most reactive nonmetals, while _____ gases are the least reactive nonmetals.

halogens noble

_____________ is a nonmetal that does not fall into a family because its chemical properties are very different from other elements. It is the simplest element, containing only one proton and one electron.

hydrogen

The most commonly known element in this series is _________________.

lanthanum (La)

To find that pattern, what did Mendeleev find for each element?

melting point density color atomic mass

have some properties of metals and some properties of nonmetals.

metalloids

list of ingredients for all matter on Earth as well as the universe

periodic table

In the periodic table, the horizontal row are called ________ and these elements do not have much in common with each other.

periods

What does the order of elements on the periodic table enables scientists to predict?

properties about the elements.

The elements in the top row are the lanthanides. These elements are all found in nature and are sometimes called the '________ __________ ___________.' What are they and what are they used for?

rare earth metals a soft, shiny metal batteries for hybrid cars and in permanent magnets

What does halogen mean?

salt forming

elements that are electrically conductive, but more malleable (softer) ex. using gold, copper, and nickel in electronic circuits because they are easier to work with and conduct electricity well

transition metals

The elements in Group 2 that are harder and more dense, and melt at a higher temperatures than the alkali metals. Also not found uncombined in nature. Very reactive, but not as reactive as alkali metals

alkali earth metals

What do alkali metals and alkaline earth metals have in common? How are they different?

alkali metals and alkaline earth metals - similarities both never found as free elements in nature (only found in compounds) both very reactive (alkali more reactive though) alkali metals and alkaline earth metals - differences alkalis are very soft, alkaline earth metals are hard and melt at higher temperatures

In the 1st column, group 1, are the _________. metals They are great __________, but are also very ___________ so they can't be used on their own.

alkaline conductors reactive

An arrangement of the elements showing the repeating pattern of their properties

periodic table

element with the simplest atom and is very rarely found on Earth as a pure element. Much of the sun is composed of this element. Why?

Hydrogen most of it combines with Oxygen in water

Under the lanthanides are the _____________. Uranium and thorium are the only two actinides that are found in significant quantities in nature. Most other actinides are not found in nature, but are made artificially in __________________. One characteristic that all actinides have in common is that they are _________________.

actinides laboratories radioactive

Why do elements need to be organized?

makes them easier to use because you can better know their properties, or characteristics. Items grouped together are likely to have some properties that are similar. It allows scientists to predict an element's properties by its location in the periodic table

As you look from left to right across a period, you will notice that the properties of the elements change in a pattern. __________ are shown on the left of the table, and ___________ are located on the right. ____________ are found between the metals and nonmetals. This pattern is repeated in each period.

metals nonmetals metalloids

this group does not ordinarily form compounds some synthesized in laboratories Helium is a common element in this group

noble gasses

a horizontal row of elements in the periodic table

period

What is new substance is created with iron and oxygen combine? This is an example of a what?

rust chemical change

What is new substance is created when sodium metal and chlorine gas combine? This is an example of a what?

sodium chloride (NaCl) table salt chemical change

the average mass of all the isotopes of that element.

the atomic mass

What did Mendeleev (men duh LAY ef) discovered about the elements?

they have a set pattern some had similar chemical and physical properties