As far as I know, the answer is B (breaking a rock)
4.648 gm of solute is needed to make 37.5 mL of 0.750 M KI solution.
Solution:
We will start with the Molarity

Also we know 1000 ml = 1 L
Therefore 37.5 ml by 1000ml we obtained 0.0375L
Equation for solving mole of solute

Now, multiply 0.750M by 0.0375
Substitute the known values in the above equation we get

Also we know that Molar mass of KI is 166 g/mol
So divide the molar mass value to get the no of grams.

So 4.648 gm of Solute is required for make 37.5 mL of 0.750 M KI solution.
Answer:
Scientists know that today the Earth's magnetic field is powered by the solidification of the planet's liquid iron core. The cooling and crystallization of the core stirs up the surrounding liquid iron, creating powerful electric currents that generate a magnetic field stretching far out into space.
Isotopes of any given factor all incorporate the equal variety of protons, so they have the identical atomic wide variety (for example, the atomic wide variety of helium is usually 2). Isotopes of a given factor include exceptional numbers of neutrons, therefore, special isotopes have special mass numbers.
Answer:
C-Electrical energy changed into mechanical energy
Explanation:
Energy, according to the law of conservation of energy, is said to neither be created or lost but only interchangeable from one form to another. Energy exists in different forms. The process by which one form of energy changes to another is called TRANSFORMATION of energy.
However, certain household appliances or devices bring about this transformation of energy. For example, in a case where Tony turns a fan on when his room becomes uncomfortably hot. The fan uses an electric source to get powered on, which then facilitates the blades of the fan to move fast in order to bring about a cool atmosphere.
The fan converts ELECTRICAL energy (electric source) into MECHANICAL energy (moving energy).