Science 24

Synthetic chemicals are defined as:

• Man-made substances created through chemical processes, often used in medicines, agriculture, and industry.

• Naturally occurring substances found in plants and animals.

• Chemicals produced only by living organisms through natural processes.

• Substances that cannot be used in any industrial or medical applications.

Pesticides are defined as which of the following, and what are their uses?

• Chemicals used to kill pests and protect crops from damage.

• Substances used to increase soil fertility.

• Natural fertilizers used to improve plant growth.

• Microorganisms used to decompose organic matter.

Herbicides are defined as which of the following, and what are they used for?

• Chemicals used to control or kill unwanted plants (weeds)

• Fertilizers used to promote plant growth

• Insecticides used to kill insects

• Fungicides used to control fungal diseases

Insecticides are defined as which of the following, and what are their uses?

• Chemicals used to kill insects, mainly used in agriculture to protect crops.

• Substances used to fertilize soil, mainly used to increase plant growth.

• Agents used to control weeds, mainly used in gardens and lawns.

• Compounds used to treat plant diseases, mainly used in orchards.

Chemistry can be used for cleaning by:

• breaking down stains and dirt using chemical reactions

• increasing the temperature of water only

• using only physical scrubbing without chemicals

• removing dirt by magnetic attraction

Chemistry can be used for better forms of clothing by:

• Developing fabrics with enhanced properties such as water resistance and breathability.

• Making clothes only from natural fibers without any chemical treatment.

• Using only traditional dyeing methods for all fabrics.

• Avoiding the use of any synthetic materials in clothing.

Plastics, polymers, and alloys are different from natural materials because:

• They are mostly man-made and have properties that can be tailored for specific uses, unlike natural materials.

• They are always biodegradable and found in nature.

• They are only used for decorative purposes.

• They are made entirely from plant sources.

Identify the household chemical symbols and their meanings from the following options.

• NaCl stands for table salt, H2O stands for water, NH3 stands for ammonia, and NaHCO3 stands for baking soda.

• NaCl stands for vinegar, H2O stands for bleach, NH3 stands for soap, and NaHCO3 stands for sugar.

• NaCl stands for sugar, H2O stands for alcohol, NH3 stands for baking powder, and NaHCO3 stands for salt.

• NaCl stands for baking soda, H2O stands for vinegar, NH3 stands for water, and NaHCO3 stands for ammonia.

Chemistry helps you cook by:

• Understanding how ingredients react and change during cooking.

• Making food taste bad.

• Preventing any changes in food.

• Only measuring temperature.

Chemicals can affect how you work in the hair salon, construction site, and automotive repair shop by:

• Requiring safety precautions to prevent health risks

• Making work easier without any risks

• Eliminating the need for protective equipment

• Having no impact on workplace safety