(Q).
Q: When matter changes into an entirely different substance with different chemical properties, what has occurred? Read this paragraph and choose the correct option from the provided answers: A chemical change occurs whenever matter changes into an entirely different substance with different chemical properties. A chemical change is also called a chemical reaction. Many complex chemical changes occur to produce the explosions of fireworks. An example of a simpler chemical change is the burning of methane. Methane is the main component of natural gas, which is burned in many home furnaces. During burning, methane combines with oxygen in the air to produce entirely different chemical substances, including the gases carbon dioxide and water vapor. You can watch some very colorful chemical changes occurring in the video at this URL:. Choices: - mechanical change - gaseous change - physical change - chemical change A:
(A).
chemical change

(Q).
Q: The three long muscles on the back of the knee are part of which group? Read this paragraph and choose the correct option from the provided answers: of the proximal tibia. This versatile muscle flexes the leg at the knee and flexes, abducts, and laterally rotates the leg at the hip. This muscle allows us to sit cross-legged. The posterior compartment of the thigh includes muscles that flex the leg and extend the thigh. The three long muscles on the back of the knee are the hamstring group, which flexes the knee. These are the biceps femoris, semitendinosus, and semimembranosus. The tendons of these muscles form the popliteal fossa, the diamond-shaped space at the back of the knee. Choices: - synovial joint - patella - adductors - hamstring group A:
(A).
hamstring group

(Q).
Q: The normal respiratory rate per minute in adult humans is? Read this paragraph and choose the correct option from the provided answers: Respiratory Rate and Control of Ventilation Breathing usually occurs without thought, although at times you can consciously control it, such as when you swim under water, sing a song, or blow bubbles. The respiratory rate is the total number of breaths, or respiratory cycles, that occur each minute. Respiratory rate can be an important indicator of disease, as the rate may increase or decrease during an illness or in a disease condition. The respiratory rate is controlled by the respiratory center located within the medulla oblongata in the brain, which responds primarily to changes in carbon dioxide, oxygen, and pH levels in the blood. The normal respiratory rate of a child decreases from birth to adolescence. A child under 1 year of age has a normal respiratory rate between 30 and 60 breaths per minute, but by the time a child is about 10 years old, the normal rate is closer to 18 to 30. By adolescence, the normal respiratory rate is similar to that of adults, 12 to 18 breaths per minute. Choices: - 6-12 breaths - 0-6 breaths - 18-24 breaths - 12-18 breaths A:
(A).
12-18 breaths