This science class document introduces students to the concept of viscosity in magma and volcanic eruptions. It explains that viscosity depends on a magma's composition and temperature, and identifies three main types of magma - basaltic, andesitic, and rhyolitic - along with their typical compositions in terms of elements like silicon dioxide and temperature ranges. Students will learn to define viscosity, identify magma types based on these properties, and compare how magmas flow to lava.

1. WELCOME TO
OUR SCIENCE
CLASS!

6. `

7. PROCEDURE:
1. Drop a small amount of liquid below their
names.
2. Slowly lift your paper in a slant position.
3. Count 3 seconds and place it on your
arm chair.
4. Observe.

8. Q1.Which liquid is most viscous? How do
you know?
Q2.Which liquid is least viscous? How do
you know?
Q3.Compare how these liquid flow with
how you think lava flows.

9. At the end of the discussion, the students can:
a. define viscosity; and
b. identify the type of magma and
its temperature.

10. √ It is the resistance to flow (opposite of fluidity).
√ It depends primarily on the composition of the
magma, and temperature.
VISCOSITY

11. Volcanic Eruptions
√ caused by magma expelled
onto the Earth's surface

12. 1. Basaltic magma
Silicon dioxide (SiO2) 45-55 wt%, high in Iron (Fe),
Magnesium (Mg), Calcium (Ca), low in Potassium (K),
Sodium (Na)
2. Andesitic magma
Silicon dioxide (SiO2) 55-65 wt%, intermediate. in
Iron (Fe), Magnesium (Mg), Calcium (Ca), low in Potassium
(K), Sodium (Na)

13. 3. Rhyolitic magma
Silicon dioxide (SiO2) 65-75%, low in Iron (Fe),
Magnesium (Mg), Calcium (Ca) high in Potassium (K),
Sodium (Na).

14. • Basaltic magma - 1000 to 1200℃
• Andesitic magma - 800 to 1000℃
• Rhyolitic magma - 650 to 800℃

15. Basaltic magma

16. Andesitic magma

17. Rhyolitic magma

18. • Mostly water vapor & some carbon dioxide
• Minor amounts of Sulfur, Chlorine, and
Fluorine gases

20. MAGMA TYPE CHEMICAL
COMPOSITION
TEMPERATURE
Basaltic
Magma
Andesitic
Magma
Rhyolitic
Magma

21. Criteria:
Content 10 pts
Delivery/Presentation 5 pts
Teamwork 5 pts
TOTAL 20 pts

22. IDENTIFICATION:
____1. It has a temperature of 1000℃ to 1200℃ and with the
composition of Silicon dioxide (SiO2) 45-55 wt %, high in
Iron (Fe), Magnesium (Mg), Calcium (Ca), low in
Potassium (K), Sodium (Na)
___ 2. It is caused by magma that has expelled onto the Earth's
surface.
____3. This magma has a temperature of 650℃ to 800℃.
____4. This describe the resistance to flow (opposite of fluidity)
and depends primarily on the composition of the magma,
and temperature.
____5. What is the important property in determining the eruptive
behaviour of magmas.
: