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First Five for January 12 and 13

Identify the missing particle in the following equation. What type of decay is taking place?

_{92}^{235}\textrm{U} \to\; _{90}^{231}\textrm{Th}\; +

Identify the particle formed when an atom of aluminum-28 undergoes beta decay.

Posted in Chemistry, First Five

First Five for January 10 and 11

Draw Lewis electron dot structures for the following diatomic molecules:

Hydrogen (H2), nitrogen (N2), Oxygen (O2), Fluorine (F2)

 

Posted in Chemistry, First Five

First Five for January 9

Match the vocabulary term on top with the definition below.

Theory, Hypothesis, Experiment, Observations

_____________________Information obtained through the senses

_____________________A well tested explanation for a broad set of observations

_____________________A proposed explanation for an observation

_____________________A repeatable procedure that is used to test a hypothesis

Posted in Chemistry, First Five

First Five for December 8 and 9

Draw Lewis electron dot structures for the following diatomic molecules:

  • H2

  • O2

  • Cl2

  • N2

Posted in Chemistry, First Five

First Five for December 6 and 7

Write the electron configuration notation and the Lewis dot notation for an atom of sulfur (S), atomic number 16. Name two other nonmetals that would have the same number of valence electrons.

Write the electron configuration notation for a sulfide ion.

Posted in Chemistry, First Five

First Five for December 5

Assume that circle “A” represents the radius of an atom of chlorine.

  1. Which circle might represent an atom of bromine?

  2. Which circle might represent a chloride ion?

  3. Which circle might represent an atom of fluorine?

 

Posted in Chemistry, First Five

First Five for December 1 and 2

Write the correct formula for each of the following compounds:

  • Sulfur trioxide
  • Sodium sulfide
  • Carbon tetrachloride
  • Aluminum chloride
  • Diphosphorus pentoxide
  • Barium phosphide
Posted in Chemistry, First Five

First Five for November 29 and 30

Put these elements in order of increasing atomic radius:

  1. Potassium (K), Cesium (Cs), Sodium (Na), Lithium (Li), Hydrogen (H)

  2. Tellurium (Te), Oxygen (O), Selenium (Se), Sulfur (S)

 

Posted in Chemistry, First Five

First Five for November 28

A particular atom has eight protons, eight electrons and ten neutrons. Answer the following questions about this atom:

  1. What element is this?

  2. What is the mass number of the element?

  3. How many valence electrons does this atom have?

  4. What is the Lewis dot notation for this atom?

  5. What is the formula and name of the ion that this atom forms?

Posted in Chemistry, First Five

First Five for November 17 and 18

Classify each of the following elements as an alkali metal, alkaline earth metal, halogen, noble gas, transition metal, nonmetal or metalloid.

  • silicon (#14)

  • rhodium (#45)

  • chlorine (#17)

  • cesium (#55)

  • argon (#18)

  • strontium (#38)

  • oxygen (#8)

  • chromium (#24)

Posted in Chemistry, First Five