Units 1 & 2- Measurement, Conversions, and Atoms

Which of the following is false about metalloids?

• They have characteristics of both metals & nonmetals

• They are semiconductors

• They form a zig-zag pattern across the left side of the periodic table

• The metalloid class is the smallest class of elements

How do you find the average atomic mass of an element?

• It is the same as the mass number

• It is the same as the atomic number

• Mass x abudance of 1st isotope & add it to mass x abundance of 2nd isotope

• Add protons and electrons

Which Number(s) does NOT have 5 significant figures?

• 15.042

• 14230

• 3.4001x10^1

• 0.00049

Using the periodic table, what is the shorthand way of writing element with atomic number 18?

• 1s^2 2s^2 2s^6 3s^2 3p^6

• [Ne] 3s^2 3p^6

• [Ar]

• 3s^2 3p^6

What are the elements called in group 8a?

• Metalloids

• Noble Gasses

• Noble Isotopes

• Alkaline elements

The middle parts of the periodic table (Groups 3-12) are called

How many electrons are in the nucleus of an atom with an atomic number of 20?

• 20 Electrons

• 18 Electrons

• 32 Electrons

• 21 Electrons

How many neutrons are in the nucleus of an atom that has an atomic mass of 36 and an atomic number of 25?

• 12 Neutrons

• 7 Neutrons

• 11 Neutrons

• 19 Neutrons