Common Assessment #1 Review

How did Henry Moseley arrange the periodic table?

• Predicting the properties of missing elements in the Periodic Table

• Providing a basis for ordering elements in the Periodic Table

• Recognizing that elements in the Periodic Table have similar properties

• Grouping elements in the Periodic Table based on their physical properties

Answer explanation

Why didn't Mendeleev organize the periodic table by atomic number?

• Atomic mass is a better way of organizing the periodic table

• There was a dispute between Mendeleev and Moseley about who could use the atomic number to organize the periodic table

• Mendeleev didn't want to use the atomic number

• Mendeleev organized the table prior to the discovery of the atomic number

Answer explanation

Mendeleev developed his periodic table based on atomic mass in the _______'s.

Moseley developed his periodic table based on the atomic number (# of neutrons) in _____.

https://www.youtube.com/playlist?list=PLHOGBLPrsnMpfXL61g8BID6oNbfg52884

Watch just the videos on Mendeleev's table and Moseley's table.

Why is Americium (#95) after Plutonium (#94) when the mass of Americium is LOWER than the mass of Plutonium?

• Elements within a period have similar behaviors

• Elements are arranged by atomic mass not atomic number

• Elements are arranged by atomic number not atomic mass

• Elements with a group have different chemical properties

Answer explanation

In 1913 Henry Moseley arranged the periodic table by atomic number after discovering that the number of neutrons was a better fit for the arrangement of the periodic table and the physical and chemical properties of the elements. This was an improvement of Mendeleev's table which was arranged in 1969 by atomic mass.

What law states that element are arranged by their atomic mass?

• Periodic Law

• Law of Conservation of Mass

• Scientific Law

• Law of Thermodynamics

Answer explanation

Other than the fact that they are gases, what are some properties of noble gases?

• All but one of them have 8 electrons in their outer shell (valence shell)

• They are generally unreactive or nonreactive (meaning they don't like to bond)

• They are colorless

• all of these

Answer explanation

They all have full valence shells... and watch the video....

In a neutral atom (no charge) the number of protons, electrons and neutrons is generally ___.

• the same

• different - the number of protons is higher

• different - the number of neutrons is higher

• different - the number of electrons is higher

Answer explanation

In the picture attached, is a neutral atom. What do you see?

How do you predict elements that have the same chemical or physical properties?

• They are in the same group or family (column)

• They are in the same period (row)

• They have the same colored letters on the periodic table

• They are in the same region on the periodic table

Answer explanation

How can you tell just by looking at a periodic table which elements are solids, which are liquids, and which are gases?

• There is no way to tell

• It depends on the table. Some have a key that shows the difference by colors.

• You have to memorize them

• If you don't have a periodic table with a key, you better have memorized the list!

Answer explanation

https://www.quora.com/How-many-elements-are-solid-liquid-and-gases-in-nature

ptable.com

The first entry on quora gives a list of the few elements that are not solid at room temperature. ptable.com has a key. Hope for a key. The table you will have on your test will NOT have a key.

Where's the largest element in a group (column)?

• The top

• The bottom

• The middle

• there's no way to tell

Answer explanation

The largest element on the periodic table is Francium. The closer an element is to Francium, the larger the element. The bottom of the column is closer to Francium.

The ionization energy of phosphorus is greater than

• Fluorine

• Oxygen

• Nitrogen

• Silcon

Answer explanation

Fluorine has the highest ionization energy on the periodic table. The closer an element is to fluorine, the higher the IE. The only element NOT closer to fluorine than phosphorus is silicon, therefore phosphorus is higher than silicon.