Mia, Daniel, and Aiden were discussing their daily routines. They realized they encounter acids or bases in different ways. Can you identify where they might have experienced acids or bases recently?

• In the food they eat

• In the cleaning products they use

• In their own metabolism

• All of the above

Answer explanation

The question asks about the recent experiences with acids or bases. The correct answer is 'All of the above' because acids and bases are present in our food, cleaning products, and even in our own metabolism. For instance, citric acid in fruits, bases in cleaning products, and metabolic processes involve acids and bases.

Anika, Liam, and Ethan are having a meal together. Anika wonders, 'What is the function of the acid in our stomachs when we eat?'

• To digest the food we eat

• To maintain cellular stability

• To clean the stomach

• To produce lactic acid

Answer explanation

The acid in your stomach primarily serves to break down the food you eat and to kill bacteria. This allows for the effective digestion of the food. Hence, the correct answer to the question is 'To digest food'.

Ava, a professional athlete, recently took a lactic acid test. How might she use this information to enhance her training routine?

• By increasing her lactic acid production

• By decreasing her lactic acid production

• By monitoring her fitness level

• By testing her blood sample

Answer explanation

A lactic acid test measures the level of lactic acid in the blood, which increases with intense exercise. An athlete can use this information to monitor their fitness level. If the lactic acid levels are too high, it indicates that the athlete may be pushing too hard and needs to adjust their workout routine. Conversely, if the levels are too low, the athlete may not be working out intensely enough and can increase their workout intensity.

During a biology class, Liam, Hannah, and Mason learn about the human body. How does the body maintain a constant balance of acids and bases in the blood?

• By producing more acids

• By producing more bases

• By regulating the levels of acids and bases

• By diluting the acids and bases

Answer explanation

The body maintains a constant balance of acids and bases in the blood through a process called homeostasis. This is achieved by regulating the levels of acids and bases, not by producing more of either or by diluting them. The body has mechanisms to either neutralize excess acids or bases or excrete them to maintain the pH balance.

Tags

NGSS.HS-LS1-3

Avery, Charlotte, and Ava are studying the roles of acids, bases, and buffers in biological systems. What is the primary role of these substances in living organisms?

• They help maintain a relatively constant pH

• They lower the pH of a solution

• They increase the pH of a solution

• They have no role in biological systems

Answer explanation

Acids, bases, and buffers play a crucial role in biological systems by helping to maintain a relatively constant pH. This is important because most biological reactions occur at a specific pH. Acids and bases can alter the pH, while buffers resist changes in pH, thus ensuring the system remains stable.

Tags

NGSS.HS-LS1-3

Zoe, Grace, and Kai are discussing how antacid tablets help soothe indigestion after a heavy meal. What is the primary action of an antacid tablet in this situation?

• By increasing the acidity of the stomach

• By neutralizing excess acid

• By producing more acid

• By removing the base from the stomach

Answer explanation

An antacid tablet soothes indigestion by neutralizing excess acid in the stomach. This helps to alleviate the discomfort caused by indigestion and restore the stomach's pH balance. The other options, such as increasing acidity or producing more acid, would worsen the condition, while removing the base from the stomach is not relevant to the action of antacids.

During a biology class, Aiden, Harper, and Samuel are discussing the role of acids and bases in cellular metabolism. What role do acids and bases play in this process?

• They help transport oxygen

• They produce lactic acid

• They regulate pH levels

• They break down food

Answer explanation

Acids and bases play a crucial role in cellular metabolism by regulating pH levels. Maintaining a stable pH is essential for various cellular processes and enzyme activities. While other options like transporting oxygen, producing lactic acid, and breaking down food are also involved in metabolism, they are not the primary roles of acids and bases.

Tags

NGSS.HS-LS2-5

Grace, Olivia, and Lily are conducting a science experiment in their school lab. They have four unknown substances and they suspect one of them to be an acid. They know some common properties of acids. Which of the following properties should they look for to confirm their suspicion?

• Bitter taste, inability to react with metals, inability to conduct electricity, inability to change the color of litmus paper

• Sweet taste, ability to react with metals to produce oxygen gas, ability to conduct electricity in solid form, ability to turn red litmus paper blue

• Salty taste, ability to react with non-metals to produce hydrogen gas, ability to conduct electricity in non-aqueous solutions, ability to turn red litmus paper green

• Sour taste, ability to react with metals to produce hydrogen gas, ability to conduct electricity in aqueous solutions, ability to turn blue litmus paper red

Answer explanation

The correct answer is 'Sour taste, ability to react with metals to produce hydrogen gas, ability to conduct electricity in aqueous solutions, ability to turn blue litmus paper red'. This is because acids are known for their sour taste, their reaction with metals to produce hydrogen gas, their ability to conduct electricity in aqueous solutions, and their ability to turn blue litmus paper red.

Aria, Nora, and Anika are conducting a science experiment in their school lab. They are testing different substances to identify their properties. They found that one of the substances has a certain set of properties. Can you guess which substance they might be testing based on these properties?

• The substance has a sweet taste, reacts with acids to form bases, and turns red litmus paper green

• The substance has a bitter taste, reacts with acids to form salts, and turns red litmus paper blue

• The substance has a sour taste, reacts with bases to form salts, and turns blue litmus paper red

• The substance has no taste, does not react with acids or bases, and does not affect litmus paper

Answer explanation

The correct answer is 'Bitter taste, react with acids to form salts, turn red litmus paper blue'. This is because bases are known for their bitter taste, they react with acids to form salts, and they have the ability to turn red litmus paper blue. These are some of the common properties of bases.

Tags

NGSS.MS-PS1-2

Charlotte, William, and Hannah are conducting a chemistry experiment. They need to maintain a stable pH level in their solution. What is the purpose of adding a buffer to their solution?

• To resist changes in pH

• To measure the pH

• To increase the pH

• To decrease the pH

Answer explanation

A buffer in a pH system serves to resist changes in pH. This means it helps maintain a stable pH level when acids or bases are added to the system. This is crucial in many biological and chemical processes where pH needs to be kept constant.