แบบทดสอบปลายภาคเรียน ที่ 2 ปีการศึกษา 2556

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The correct answer states that the chemicals used to eliminate pests should be stored separately to avoid contamination with other substances. This is important because mixing chemicals with other substances can cause chemical reactions or reduce the effectiveness of the pesticide. Therefore, it is necessary to store the chemicals in a separate container to ensure their potency and prevent any unwanted reactions or hazards.

The question asks about a possible disease that a person who regularly drinks carbonated drinks might have. The correct answer is "กระเพาะอาหาร" which means "stomach". This suggests that the person may have a stomach-related issue or disease due to the consumption of carbonated drinks.

If a student consumes crispy nuggets, they are at risk of ingesting borax.

The correct answer is "ตำลึง" because it is the only option among the given vegetables that is not commonly sprayed with harmful chemicals. Cabbage, kale, and lettuce (คะน้า, ผักกวางตุ้ง, ผักกาดขาว) are often treated with pesticides and other chemicals during cultivation, making them less safe compared to "ตำลึง".

The answer states that vegetables that have few or no signs of worms or insect bites are safe to consume. This is because vegetables with worms or insect bites may have been exposed to pesticides or other chemicals used to control pests. Therefore, choosing vegetables that are free from worms or insect bites ensures that they have not been treated with harmful chemicals and are safe to eat.

When consuming a large amount of chemicals that accumulate in plants, it often leads to symptoms such as nausea and vomiting.

The correct answer is "ยาฆ่าแมลงต้องเก็บแยกไว้ต่างหาก" which means "Insecticides must be stored separately". This answer is correct because it emphasizes the importance of storing insecticides separately from other substances. Storing insecticides separately helps prevent accidental contamination or mixing with other chemicals, which could be dangerous or reduce the effectiveness of the insecticide.

The first step in using pesticides is to study and understand the proper methods of application. This is important because using pesticides incorrectly can be ineffective or even harmful to the environment and human health. Therefore, it is crucial to have a clear understanding of how to use the pesticides before proceeding with any other steps such as cleaning the body, washing tools, or wearing protective clothing.

Mixing white cement with baking soda will cause a chemical change. When white cement (calcium oxide) reacts with baking soda (sodium bicarbonate), it produces carbon dioxide gas, water, and a compound called calcium carbonate. This reaction is known as a chemical change because it results in the formation of new substances with different properties than the original substances. Therefore, the correct answer is white cement with baking soda.

The correct answer suggests that one reason to avoid buying food with adulterated substances is to save expenses by using natural ingredients. This implies that natural ingredients may be cheaper or more cost-effective compared to processed or adulterated ones. By choosing natural ingredients, individuals can potentially save money while also avoiding the risks associated with consuming food with harmful substances.

น้ำส้มสายชู contains the highest amount of chemicals among the given options.

The most important principle of using insecticides is to stand upwind while spraying. This is because standing upwind helps to prevent the insecticide from being blown back towards the person spraying, reducing the risk of inhalation or contact with the chemical. Standing upwind also helps to ensure that the insecticide is properly dispersed in the desired direction, increasing its effectiveness in targeting the insects.

When mixed with water, quicklime (calcium oxide) undergoes an exothermic reaction, releasing a large amount of heat. This reaction is commonly used in construction to create a strong and durable bond between materials. Charcoal (carbon) also releases heat when it reacts with water, but it is not as significant as the reaction of quicklime. Salt (sodium chloride) and sugar (sucrose) do not produce heat when mixed with water. Iodine (iodine) and hydrogen peroxide (hydrogen peroxide) do not react exothermically with water either. Therefore, the correct answer is "ปูนขาว ถ่านก๊าซ" (quicklime, charcoal).

The reason why we need to use chemicals is because they provide fast results.

The correct answer is "นำไปเผาสังเกตการเปลี่ยนแปลง" which means "burn it and observe any changes". This method is used to check for counterfeit seasoning powder. Burning the powder can reveal any changes in color, texture, or smell, which can indicate that the seasoning powder is fake.

The question asks for the type of chemical that is least useful in our daily lives. Out of the given options, "ปราบศัตรูพืช" (pesticides) is the correct answer as it is a type of chemical used to kill or control pests on plants. While pesticides are important for agriculture and maintaining crop yields, they may have negative impacts on the environment and human health if not used properly. Therefore, compared to the other options like food additives, cleaning agents, and personal hygiene products, pesticides have less direct usefulness in our daily lives.

The correct answer is "ยาสูบ" because it is a type of plant that has properties to control or eliminate plant pests.

The correct answer is "ยาปราบศัตรูพืช" which translates to "pesticide" in English. Pesticides are chemicals used to control or kill pests, such as insects, weeds, and fungi, in order to protect crops and increase agricultural productivity. However, pesticides are known to be highly toxic and can have detrimental effects on the environment and human health. Therefore, they are considered to have the greatest impact on increasing pollution.

The answer choice "ลักษณะที่เปลี่ยนไปเมื่อรวมกับสารอื่น" (change in characteristics when combined with other substances) is not a physical property of a substance. Physical properties are inherent characteristics of a substance that can be observed or measured without changing its composition or identity. The change in characteristics when combined with other substances refers to a chemical property, as it involves a chemical reaction or interaction between substances.

Iron rust is a chemical reaction that occurs when iron comes into contact with oxygen in the air. When iron reacts with oxygen, it forms iron oxide, which is commonly known as rust. Therefore, the correct answer is oxygen.

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ยางมะละกอ มีความยืดหยุ่นและนุ่มนวล ทำให้เป็นวัสดุที่เหมาะสำหรับการทำเนื้อเปื่อยง่าย ในขณะที่ผิวส้มโอ น้ำปูนใส และดินประสิวไม่มีคุณสมบัติที่เหมาะสำหรับการทำเนื้อเปื่อย ดังนั้น ยางมะละกอเป็นคำตอบที่ถูกต้องสำหรับการให้เนื้อเปื่อยง่าย

Soaking vegetables in a 0.5% vinegar solution (แช่น้ำส้มสายชู 0.5%) helps to reduce pesticide residues the most. Vinegar is known for its ability to remove pesticide residues from fruits and vegetables. The acidity of vinegar helps to break down and remove the pesticides, making it an effective method for reducing pesticide residues on vegetables.

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Students would choose to use the substance "เจนเชี่ยนไวโอเลต" to test for genuine orange juice.

ทองเหลือง is the correct answer because it is a mixture of gold and other metals, specifically copper. It is an alloy that is commonly used in jewelry and has a distinct yellow color.

ปูนขาว (lime) is beneficial in adjusting the acidity of water because it is an alkaline substance. When added to water, it can neutralize excess acidity by increasing the pH level. This is commonly done in water treatment processes to balance the pH and make the water less acidic.

The question is asking which criterion is used to categorize ด่างทับทิม (tamarind juice) and เกลือแกง (curry paste) in the same category. The correct answer is "ความเป็นเกลือปนอยู่" (the presence of salt). This means that both tamarind juice and curry paste have salt in them, which is the criterion for categorizing them together.