Experiment: The properties of sea water

It may have happened to you too, while you are bathing in the sea, to drink some water, and you will have noticed that it is very salty. An experiment of about half an hour with water, an egg and a pinch of salt to begin to know the sea, starting from the concept of salinity to understand the concept of density of water, discovering the differences between sea water and fresh water.

Instructions for use:

Use the document online or in paper format, as a recreational activity at home or during a lesson at school.

Materials needed:

tap water, 2 empty clear glasses, 2 fresh raw eggs, 1 cooking spoon, fine cooking salt, labels, pencil.

Procedure:

1. Prepare the labels and apply them to the glasses to distinguish them
2. Arrange the glasses and pour:

• Glass 1: water
• Glass 2: water and 2 heaped tablespoons of fine salt, stirring to dissolve

3. Try to think…what will happen when we put an egg in the two glasses? Will it float or sink? Write down your hypotheses.
4. It is time to put the eggs in the glasses. Gently drop an egg into each glass.
5. Watch what happens…your hypotheses have been verified. Try to give an explanation for what you observe in your own words.

Cognitive learning objectives:

• The student understands the basic concepts of different densities of ocean water.
• The student knows the physical and chemical properties of ocean water.

Social-emotional learning goals:

• The student is able to advocate for sustainable ocean management.
• The student is able to understand different perspectives on the impact of daily life on the ocean.
• The student is able to perceive the human connection between climate change and human health

Behavioral learning objectives:

• The student is able to express his/her personal relationship with the sea.
• The student is able to talk about the ocean and climate change with knowledge.
• The student is able to understand the importance of protecting the ocean.
• The student is able to make informed decisions regarding the ocean.
• The student is able to talk about the ocean correctly, in a coherent and informed way.
• The student is able to investigate the relationship of dependence of life on the sea.
• The student is able to understand the importance of protecting the ocean.

UNESCO Education for Sustainable Development Approaches:

Geographical perspective, scientific perspective.

Connection between subjects:

Marine ecology, natural sciences, physics, chemistry, technology.

Sustainable Development Goals:

• SDG 14 “Life Below Water”
• SDG 4 “Quality Education”

Connection to Ocean Education Principles:

• Principle 1 “The Earth has a large ocean with many features”
• Principle 2 “The ocean and life in the ocean shape the features of the Earth”
• Principle 3 “The ocean has a major influence on climate and weather”