4Q IS LE1

• Water has a chemical formula of H2O. The molecules form a V-shaped structure. It is made up of two hydrogen atoms and one oxygen atom. It is joined together by a covalent bond.
• Covalent bond is when atoms are bonded through the sharing of electrons.
• Oxygen has partially negative charges, hydrogens have partially positive charges.
• Opposite charges attract.
• H2O is a polar molecule, meaning there is an unequal distribution of electrons in the molecular structure.
• Hydrogen bond is when a partially positive hydrogen is attracted to the water molecules’ partially negative oxygen.
• Cohesion is when water molecules are attracted to each other.
• Surface tension happens when the cohesive force is so strong it can resist an external force.
• Adhesion is when water molecules get attracted to other molecules or substances.
• Water is a good solvent.
• Capillary action is when cohesion and adhesion of water enables them to move upward in a narrow tube.
• The smaller the radius, the greater the height of the water.
• When water cools below 4°C, it moves slowly and expands until it freezes into a solid at 0°C. The water molecules align into a crystal lattice and spaced further apart. he lattice structure of ice makes it less dense, enabling it to float on water.
• 4°C = expands

  0°C = freezes

  100°C = boils
• Specific heat capacity is the amount of energy needed to increase the temperature of one gram of substance by one degree Celsius.
• The greater the specific heat capacity, the greater the heat required to produce a given increase.
• Heat is needed to be absorbed first to break hydrogen bonds.
• Once the water reaches boiling point, the kinetic energy of H2O molecules increases that break

  hydrogen bonds. Free water molecules move towards the surface of a pot of boiling water as water

  is turned into water vapor (gaseous state).
• Water molecules lose energy and move slowly. At 0°C, each water molecule is “hydrogen-bonded” to four partners into a crystalline lattice, makes ice (solid water) less dense than the liquid.
• Heat of vaporization is the amount of heat needed to turn 1 gram of a liquid into a vapor.
• All liquid can be changed into a gas phase if enough heat energy is added
• Vaporization or evaporation is when heat energy is added, the liquid’s average kinetic energy will increase, enough to break molecular attractions and escape the air as a gas.
• Evaporation occurs anywhere.
• Evaporative cooling is the surface of the liquid where evaporation occurs cools down.
• The hottest molecules (greatest amount of kinetic energy) will most likely leave as gas.
• The radiation/thermal energy from the sun is the most important part of the renewal of the water cycle.
• (2) Sun gives water energy to turn it to water vapor through evaporation.
• (3) Plants and trees lose water through transpiration.
• (4) When ice caps are heated it is sublimation.
• (5) The water vapor rises up, cools, turns back into liquid, forming tiny droplets by condensation.
• Gravity pulls water back to Earth’s surface in the form o rain, sleet, or snow by precipitation.
• When precipitation is soaked into the ground and trapped between layers of rocks and clay, becoming ground water, it is called percolation.
• Gravity pulls most of the water downhill towards the ocean, they are called runoff.
• Ocean makes up 97% of all earth’s water
• Only 3% of Earth’s water is fresh
• Water with little or no dissolved salt is called Freshwater
• Freshwater is mostly found as water vapor in air or moisture in ground
• 79% of freshwater is. locked in glaciers or ice caps
• Groundwater is water found underground in saturated zones beneath the earth surface
• The upper portion of the ground saturated with water is called the water table