Helium
Helium is a chemical element with the symbol He and atomic number 2. It is a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gas group in the periodic table. Its boiling and melting points are the lowest among the elements and it exists only as a gas except in extreme conditions.
Properties of Helium:
- Atomic number: 2
- Symbol: He
- Boiling point: -268.9°C
- Melting point: -272.2°C
- Density: 0.1786 g/L
- State at room temperature: Gas
- It is the second lightest element
Uses of Helium:
Helium is widely used for filling balloons, as a carrier gas for chromatography, and as a coolant for nuclear reactors and in cryogenics. It is also used in the production of silicon wafers and to detect leaks in high-vacuum equipment.
Study Guide Questions:
- What is the atomic number of helium?
- What are the boiling and melting points of helium?
- What is the state of helium at room temperature?
- What are the main uses of helium?
◂Science Worksheets and Study Guides Third Grade. Relationships among living things
Study Guide
Relationships among living things 
Activity Lesson
Relationships Among Living Things Worksheet/Answer key
Relationships among living things Worksheet/Answer key
Relationships among living things Worksheet/Answer key
Relationships among living things Worksheet/Answer key
Relationships among living things Vocabulary/Answer key
Relationships among living things Vocabulary/Answer key
Relationships among living things
Activity LessonWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyWorksheet/Answer keyVocabulary/Answer keyVocabulary/Answer keyThe resources above cover the following skills:
LIFE SCIENCE
From Molecules to Organisms: Structures and Processes
Create representations to explain the unique and diverse life cycles of organisms other than humans (e.g., flowering plants, frogs, butterflies), including commonalities such as birth, growth, reproduction, and death.
Unity and Diversity
Construct an argument from evidence to explain the likelihood of an organism’s ability to survive when compared to the resources in a certain habitat (e.g., freshwater organisms survive well, less well, or not at all in saltwater; desert organisms survive well, less well, or not at all in woodlands).
Create models that illustrate how organisms and their habitats make up a system in which the parts depend on each other.