Nature's Classroom: Water

Seawater is salty because of the minerals dissolved in it. Waterfalls are created by the flow of water over a precipice.

Format: Hardback
Length: 32 pages
Publication date: 10 August 2023
Publisher: Hachette Children's Group

Why is seawater so salty?
Seawater is salty because it contains a high concentration of dissolved salts and minerals. These salts and minerals are primarily sourced from two main sources:
1. Evaporation: When seawater evaporates, the water molecules are left behind, along with the dissolved salts and minerals. As the water evaporates, it leaves behind a concentrated solution of salts and minerals in the remaining water.
2. Input from rivers: Rivers carry dissolved salts and minerals from the land into the ocean. As the rivers flow into the ocean, they deposit their sediment, which contains a mixture of salts and minerals. Over time, these deposits build up and contribute to the salinity of seawater.
The salinity of seawater is an important factor in the marine ecosystem, as it affects the behavior and physiology of marine organisms. Seawater with a high salinity can be harsh and inhospitable to many marine species, while seawater with a low salinity can be more conducive to their survival.

How are waterfalls created?
Waterfalls are created by the flow of water over a steep incline. The water begins to flow down the slope, picking up speed and momentum as it goes. As the water reaches the bottom of the slope, it encounters a resistance force, which causes it to break up into droplets and fall back down the slope.
There are several factors that can influence the formation of waterfalls, including:
1. Elevation: Waterfalls are typically formed at high elevations, where the water has to flow over a significant distance before it can fall back down the slope.
2. Gravity: The gravitational force of the Earth plays a crucial role in the formation of waterfalls. Water that flows down a steep slope has a greater gravitational force, which causes it to accelerate and break up into smaller droplets.
3. Water flow: The speed and volume of water flowing over a slope can also influence the formation of waterfalls. Water that flows quickly and in large quantities can create a more powerful and dramatic waterfall.
4. Sedimentation: Over time, the sediment carried by the water can build up on the slope, creating a more gradual and gentle slope that can lead to the formation of a waterfall.
Waterfalls are a beautiful and awe-inspiring natural phenomenon that can be found in many different parts of the world. They are a testament to the power of water and the forces of nature that shape the world around us.

Weight: 336g
Dimension: 216 x 272 x 10 (mm)
ISBN-13: 9781526322630