How many neutrons does element X have if it's atomic number is 21 and it's mass number is 75

How much heat is needed to raise the temperature of 8g of water by 20oC?

Jill applies a force of 15 N to a wrench. If the wrench applies a force of 150 N to a bolt, which of these values is the input force and which is the output force?

What causes a tsunami to grow taller as it reaches the shore?

What can be known about the density of sodium hydroxide? A. It will be 2.54 g/cm². B. It will be different from the other chemicals. C. It will be 1.67 g/cm3. D. It will be the same as the other reactant.

The gravitational force between two objects will be greatest in which of the following situations? A Both objects have small masses are close together. B One object has a large mass, and the objects are close together.

A major obstacle to developing good human relations is that

4.) An apartment building is on fire and a guy is trapped on the fire escape ladder. There is a dumpster that is 6.3m away and is filled full of trash, and he is 7m above it.

Calculate the temperature of and power-per-area radiated from a blackbody if the spectral intensity density peaks at (a) gamma rays, λ = 1.50*10-14 m; (b) x rays, 1.50 nm; (c) red light, 640 nm; (d) broadcast television waves, 1.

How has increased energy use associated with scientific advancements affected society? a. It has led to an increase of the concentration of atmospheric carbon dioxide. b. It has led to an increase in hazardous wastes from mining operations. c.

Water is moving with a speed of 5.7 m/s through a pipe with a cross-sectional area of 4.8 cm2. The water gradually descends 9.2 m as the pipe increases to 8.8 cm2. (a) What is the speed at the lower level? (b) If the pressure at the upper level is 1.