Gold

Gold is a chemical element with the symbol Au (from Latin: aurum) and atomic number 79, making it one of the higher atomic number elements that occur naturally. It is a dense, soft, and malleable metal with a bright yellow color and luster that is considered attractive. Gold is a precious metal and has been used for coinage, jewelry, and other arts throughout recorded history.

Physical and Chemical Properties

Gold is a transition metal and is solid at room temperature. It is a good conductor of heat and electricity. Gold is resistant to corrosion and tarnishing, making it extremely durable. It does not react with oxygen or water, which is why it maintains its shine and luster over time.

Occurrences and Extraction

Gold is found in nature in a variety of forms, but it is most commonly found as nuggets or grains in rocks, rivers, and alluvial deposits. It can also be found in combination with other minerals, such as quartz and pyrite. Gold is extracted from these ores through various methods, including cyanidation, smelting, and leaching.

Uses

Gold has a wide range of uses, including:

Manufacture of jewelry and decorative items
Electronics, such as connectors and wires
Medical applications, including dentistry and treatment of certain medical conditions
Investment and currency (gold bars and coins)

Environmental Impact

Gold mining and extraction can have significant environmental impacts, including habitat destruction, soil and water contamination, and disruption of ecosystems. Efforts are being made to develop more sustainable and environmentally friendly methods of gold extraction and mining.

Study Guide

Here are some key points to remember when studying gold:

Gold is a chemical element with the symbol Au and atomic number 79.
It is a dense, soft, and malleable metal with a bright yellow color and luster.
Gold is resistant to corrosion and does not tarnish.
It is found in nature as nuggets, grains, or in combination with other minerals.
Gold is used in jewelry, electronics, medicine, and as an investment.
Gold extraction and mining can have significant environmental impacts.

◂Science Worksheets and Study Guides Seventh Grade. Ecosystems, food chains and food webs

Study Guide

Ecosystems, food chains and food webs

Activity Lesson

Ecosystems, Food Chains & Food Webs

Worksheet/Answer key

Ecosystems, food chains and food webs

Worksheet/Answer key

Ecosystems, food chains and food webs

Worksheet/Answer key

Ecosystems, food chains and food webs

Vocabulary/Answer key

Ecosystems, food chains and food webs

Vocabulary/Answer key

Ecosystems, food chains and food webs

Vocabulary/Answer key

Ecosystems, food chains and food webs

Vocabulary/Answer key

Ecosystems, food chains and food webs

Vocabulary/Answer key

Ecosystems, food chains and food webs

The resources above cover the following skills:

LIFE SCIENCE

Ecosystems: Interactions, Energy, and Dynamics

Examine the cycling of matter between abiotic and biotic parts of ecosystems to explain the flow of energy and the conservation of matter.

Analyze and interpret data to provide evidence regarding how resource availability impacts individual organisms as well as populations of organisms within an ecosystem.

Construct an explanation to predict patterns of interactions in different ecosystems in terms of the relationships between and among organisms (e.g., competition, predation, mutualism, commensalism, parasitism).

Engage in argument to defend the effectiveness of a design solution that maintains biodiversity and ecosystem services (e.g., using scientific, economic, and social considerations regarding purifying water, recycling nutrients, preventing soil erosion).