Mystery Seed of the Week 222

This photograph is a public domain image that I have cropped to remove the species name. I will reveal the full image in the answer. (It comes with a story).

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Do you recognize what plant the seeds are from? If you choose to, please leave a comment with your ideas.

(New mystery seeds and Seed of the Week answers are posted on Tuesdays.)

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Seed of the Week: Tickseed Sunflower

Our mystery seeds from last week were indeed tickseed sunflowers or common beggarticks, Bidens frondosa.

At least I think they are tickseed sunflowers. There are a number of similar species in the Genus Bidens. If you have a specimen you’d like to identify and you know a little botanical vocabulary, you might try this key.


The seeds of the tickseed sunflower form in these interesting seed heads.


The seeds then catch and stick to passing animals, in this case my jeans.


The  flowers are small clusters of yellow. They are not very showy.


The leaves are compound, mostly in groups of three.

Tickseed sunflowers are native to North America and are often found growing in wet areas throughout the continent.

Although the plants can be considered to be a nuisance because of the sticky seeds, the seeds are much easier to remove than burdocks, and they are useful as food for wildlife.The plants are eaten by muskrats, rabbits, and caterpillars. The seeds are eaten by small rodents and birds, particularly waterfowl.

If you have a microscope and someone brings some home on their socks, be sure to take a peek at these fascinating seeds.

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National Chemistry Week Plus National Mole Day

Interested in Chemistry? Then this is a big week for you because it is National Chemistry Week from Sunday, October 19, 2014 to Saturday, October 25, 2014, plus Mole Day is Thursday, October 23 from 6:02 a.m. to 6:02 p.m!

NCW 2014 - CandyThe theme for Chemistry Week this year is “The Sweet Side of Candy.” Isn’t that perfect for the days leading up to Halloween?

Candy Chemistry Experiment Links:

I have been teaching a high school chemistry class, and one of the activities we did was place M&M candies in groups by color on a paper plate and then carefully cover them with water. The dyes in the candy coating go into solution, but don’t mix readily. See more about it in a post at East Valley Chemistry Club.

The NISENetwork has suggestions for candy-related chemistry activities and experiments, including an old favorite, candy chromatography.

Candy chromatography is popular. A similar experiment uses a water solution to make spots on a coffee filter.

Chocolate science is always fun. This chocolate experiment is for older kids interested in food science studies the process of tempering. It does require heat and special ingredients.

Steve Spangler’s Science has several candy-related experiments:

1. This experiment uses pop rocks popping candy and soda to explore how this candy gets its bang.

2. Mentos candy and diet soda always causes a big splash.

If you have some time on your hands, try Making Rock Candy. Use the recipe to make some sugar crystals.

Will studying all this candy science ever be useful in the future? Check out the videos from the American Chemistry Society that discuss some sweet careers in chemistry and food science.



Mole Day, Thursday October 23

Mole Day commemorates Avogadro’s Number or 6.02 x 1023. It is held on 10/23 (October 23) from 6:02 a.m. to 6:02 p.m.

Some ways to celebrate:

  • Make some guacamole with avocados and eat with 6.02 corn chips (avocados can be used to study oxidation, too).
  • Make and drink a glass of molasses milk (try stirring 1 tsp. dark molasses into 8 oz milk, soy milk, rice milk or almond milk).
  • Bake molasses cookies and share 6.02 of them or eat one at 6:o2 p.m.
  • Figure out how much aluminum foil you would need to make a 1.0 mole aluminum foil sculpture*.

How do you determine one mole of some substance weighs? For a specific atom, you can use the atomic mass from a periodic table to figure out how much a mole of that atom weighs. For example, one atom of hydrogen has an average mass of  about 1 amu. Converting to grams,  one mole of hydrogen atoms (6.022 x 1023 of them) has an average mass of about 1 g, but because hydrogen gas is normally in the form of H2, a mole of hydrogen gas would be 2 grams.

For molecules, add up the atomic mass units for the atoms in the molecule. Therefore, one mole of H2O is the mass of two hydrogen atoms (2) plus the mass of one oxygen atom (16), or approximately 18 g.

*Hint:  The atomic mass unit of Al is 26.982 or about 27.

However you choose to celebrate it, this week is a great time to think about chemistry and the mole.

If you choose to share, how are you going to honor Mole Day?

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