As I sit here typing, the first real snow of the year is falling outside my window. Though it looks beautiful on the trees and lawn, I'm dreading going out later to drive my son to his hockey game!
Fortunately, the weather was predicted and the roads have been treated, so the drive shouldn't be that bad.
Why treating the roads is helpful...
Fresh water freezes at 32 degrees Fahrenheit but seawater freezes at about 28.4 degrees Fahrenheit , because of the salt in it. - NOAA's National Ocean Service
When salt - NaCl or Sodium Chloride, is added to water, the salt dissolves. According to Fred Senese from Frostburg University, the dissolved NaCl molecules "do not pack easily into the array of molecules in the solid" as water is becoming ice in cold weather - they make it more difficult for water to change to a solid by getting in the way of the water molecules forming a crystal. The temperature has to be even colder for saltwater to become a solid ice.
What happens when the snow melts?
When the snow melts, the salt water from the treated roads can be absorbed by plants and trees or run off into streams and lakes - which can be toxic to plants, trees and aquatic organisms.
Cells and Salt...
We all know that if we're lost at sea that we shouldn't drink the salty sea water since it will dehydrate us, making us even more thirsty!
When cells of living things are exposed to a higher concentration of solute, such as salt water or sugar water, water will leave the cells causing them to shrivel. The cells are said to be in a hypertonic solution.
Below is a picture of red blood cells in an isotonic solution - how they are normally found, and in a hypertonic solution of salt water. See how shrunken and wrinkled they become in a hypertonic solution!
A shrivelled cell has a tough time doing its job!
Road Salts and the Bay...
Sharing a little bit of science in our everyday world .
Email to Class
Class Pics on Twitter
Science of Hockey
Road Salt and Ice
Blog Story - Science!
Snow - Climate Change
Flood in Ellicott City
Reindeer, Moose, Musk-ox
Oil, Gold, Power
Why I Blog
View Meteor Shower
Iron Age to Van Gogh - Native/Invasive species
Forest to Spa
Delaware to Germany/Grow Hedges
Space-A Vacation/How Planes Fly
Snake in my Yard
Assasin Bugs/Japanese Beetles
Venus Fly Trap
Blogs I Follow:
DNA Science Blog
Endless Forms Most Beautiful
Mom's Big Year