How many number of electron shells does calcium have?

Suppose the moon rotated on its axis just as quickly as Earth. Would you still always see the same side of the moon from Earth?

Calculate the pH of hydronium ions in a 0.000 01 M solution of the strong acid HI.

a 20000kg railroad car is rolling 6.00m/s when 7000kg olaf id gravel is suddenly dropped in. What's the cars speed after gravel is loaded?

What happens when you brake earphones in to smaller and smaller pieces

A girl sits on a tire swing and is pushed in a circular motion by her father. Her tangential speed is 2.8 m/s and the girl travels in a circle with a diameter of 4.0 m. What is the girl's centripetal acceleration?

A fisherman noticed that a float makes 30 oscillations in 15 seconds. The distance between two consecutive crests is 2 m. What is the period and frequency of the wave? What is the wave speed?

A small spaceship with a mass of only 2.6 ✕ 103 kg (including an astronaut) is drifting in outer space with negligible gravitational forces acting on it. If the astronaut turns on a 12 kW laser beam, what speed will the ship attain in 1.

What will be the acceleration of a skydiver when air resistance builds up to 86% of her weight? assume the acceleration due to gravity is 10 m/s 2. answer in units of m/s 2?

A 255 g lead ball at a temperature of 81.6°C is placed in a light calorimeter containing 153 g of water at 22.3°C. Find the equilibrium temperature of the system.

Using the equation T=2π√L/g solve for L