AP Chem Things You Should Know

Round the following number to four significant figures and express the result in scientific notation: 229.613

• 0.2296 X 10³

• 229.6

• 2.296 x 10^-2

• 2.296 X 10²

• 22.96 x 10^-1

If my charge becomes 2+ what does that say about me?

• I am stealing 2 electrons

• I am losing 2 electrons

• I am in period 2

• I have an atomic # of 2

Tags

NGSS.HS-PS1-1

If an atom has 8 protons and 10 electrons, what is its charge?

• Positive
• Neutral
• Negative
• It depends on its size

24.1% of all the isotopes of a an element have a mass of 75.23 amu, 48.7% have a mass of 74.61 amu, and 27.2% have a mass of 75.20 amu.
What is the average mass of this element?

• 74.92 amu
• 24.97 amu
• 75.01 amu
• 74.51 amu

The mass spectrum of a sample of an element is shown below. What is the average atomic mass of this element?

• 69.0

• between 69.0 and 70.0

• 70.0

• between 70.0 and 71.0

NH₄⁺ is the formula for which ion?

• ammonia

• ammonium

• nitrogen tetroxide

• amine

The difference between an ion ending in -ite and an ion ending in -ate is

• the -ate ion is 2+; the -ite ion is 2-

• the -ate ion is 2+; the -ite ion is 1+

• the -ate ion is contains one more oxygen than the -ite ion

• the -ate ion is contains one less oxygen than the -ite ion

The formula for the nitrate ion is

• N^3-

• NO^3-

• NO₂^-

• NO₃^-

CN^- is the formula for the

• acetate ion

• cyanate ion

• cyano ion

• cyanide ion

The correct formula for the permanganate ion is

• MnO₄^-

• MNO^4-

• KMnO₄^-

• MnO₄^2-