Question

1. according to the information in the article, the earth acts like a giant magnet. which of the following is correct about the earth’s magnetism?

a. earth’s mantle is made up of silver and nickel, which gives it a magnetic sphere.
b. earth’s core is comprised of iron and nickel, which causes its magnetic field.
c. the core of the earth is made up of iron and copper, giving it a magnetic field.
d. the mantle of the earth is comprised of gold and cobalt, causing its magnetic sphere.

1. magnets can be used in everyday life. what does mri stand for? what does the magnetism in an mri help accomplish?

Explanation:

Question 3

To determine the correct option about Earth's magnetism, we analyze each choice:

• Option a: Earth's mantle is not made of silver and nickel. The mantle is mainly silicate - rich, so a is incorrect.
• Option b: Earth's core is composed of iron and nickel. The movement of the liquid outer core (composed of iron - nickel alloy) generates Earth's magnetic field, so b is correct.
• Option c: Earth's core is not made of iron and copper. It is iron - nickel based, so c is incorrect.
• Option d: Earth's mantle is not made of gold and cobalt. The mantle is silicate - rich, so d is incorrect.

• What does MRI stand for? : MRI stands for Magnetic Resonance Imaging. It is a medical imaging technique that uses a strong magnetic field, radio waves, and a computer to produce detailed images of the organs and tissues within the body.
• What does the magnetism in an MRI help accomplish? : The strong magnetic field in an MRI aligns the protons in the body's hydrogen atoms. When radio waves are applied and then turned off, the protons emit signals as they return to their normal state. These signals are detected and used by the computer to create detailed cross - sectional images of the body. This helps in diagnosing various medical conditions by visualizing internal structures such as the brain, spinal cord, joints, and internal organs, allowing doctors to detect abnormalities like tumors, injuries, or diseases. Also, the magnetism helps in distinguishing different types of tissues based on their proton density and relaxation times, providing more detailed and accurate information compared to some other imaging techniques.

Answer:

b. Earth’s core is comprised of iron and nickel, which causes its magnetic field.

Question 4