Matter and forces Grade 4

1. MATTER, MASS AND VOLUME

Matter: everything with mass and volume.

Mass: amount of matter in a body. We measure it in grames and kilogrames.

Volume: it´s the amount of space that something occupies. Measure: litres.

Density: it expains why some objects float on water and why others sink. We calculate it by dividing the mass of an object by its volume.
     
D=      mass      
         volume
Example:
Cork: 0,25 Kg/l
Water: 1,00 Kg/l
Iron:  7.90 Kg/l        Which one will float? and sink? Why?

Game about matter, mass and volume: http://www.e-learningforkids.org/science/lesson/iceland-mass-volume-matter/

EXPERIMENT I: Float the egg

EXPERIMENT II:  relationship among matter, mass and volume.
2. Changes in matter: PHYSICAL AND CHEMICAL CHANGES

Physical changes: matter has 3 forms: solid, liquid and gas. A physical change occurs when matter changes shape or state.

Reversible physical change: If we can turn the sustance back to its original form.

Ex: Fusion: change from a solid state to a liquid state. (ice→water)
      Solidification: change from liquid state to a solid state (freeze)
      Evaporation: change from a liquid state to a gas state
      Condensation: change from a gas state to a liquid state.

                                 

                                                    

Irreversible physical change: We can´t turn the substance back to its original form. Ex: when we break a glass. 

Chemical changes: when a NEW substance is produced.

Examples:

• Combustion: occurs when a material (such as wood) combines with oxygen and burns. The wood/paper transforms into new substances: smoke and ash. 
  
• Oxidation: when a substance in some metals combines with the oxygen in the air and with water→a new substance called "rust" is formed.
  
• Putrefaction: occurs when organic matter decomposes. (bacteria) 

  

  
  Game online: http://www.ecosystemforkids.com/games/4th-grade/physical-and-chemical-changes/activity.html
  https://infograph.venngage.com/ps/uxBJ1QJxXeM/physical-vs-chemical-changes
  

  
  

  

  

  

  
  

  

  
  

  
  

  
  3. MIXTURES
  

  
  Definition: A mixture is something that contains 2 or more different materials. Ex: Salt water (water+salt+other minerals); rocks (different types of minerals).

  Types ox mixtures: homogeneous or heterogeneous

  

  
  

  

  Quizz: homogeneous or heterogeneous? https://quizizz.com/admin/quiz/56baa82e5e3ecef35463b9be

  Worksheet.
  Game online: http://www.ecosystemforkids.com/games/2nd-grade/mixtures/activity.html
  
  
  

  METHODS TO SEPARATE MIXTURES:

  • Filtration: to separate solids from liquids. 
    

  
  

  
  

  
  

  • Distillation: to separate homogeneous mixtures.

  
  

  • Evaporation: to separate homogeneous mixtures of a liquid and a solid (Ex: water and salt).

  
  

  
  

  Activity 1: How can you separate these mixtures?
  
  -Pizza
  Small stones and coke
  -Cereals and milk
  -Salt and water
  -Frui salad
  -Wine (Alcohol)
  
  Activity 2: Matching worksheet: https://www.greatschools.org/library/cms/29/25729.pdf
  
  Activity 2: complete the schemes in your notebook.
  Extra: put two examples of mixtures and decide how to separate them.

  
  

  4. FORCES

  -Contact forces: They act when 2 bodies touch each other.

  -Types:

  • Gravity: it causes objects to fall to the ground

  • Magnetism: force of attraction or repulsion caused by magnetic materials. Magnets have 2 poles: north pole and south pole.

                  -SAME poles together: magnets repeal each other. 

                  -OPPOSITE poles: magnets attract each other.

  

  CONCEPTUAL MAP