Why do electrons occupy equal energy orbitals singly before beginning to pair up?

An electronic circuit element consists of 23 mg of silicon. An electric current through the circuit adds heat at a rate of 7.4 x 10-3 J/s.

What is the concentration of Sr2 + in a saturated solution of SrSO4? SrSO4 has a Ksp of 3.2 x 10-7

Which of the following is an acid-base indicator? A) hydrochloric acid B) sodium hydroxide C) water D) phenolphthalein

A pinball bangs against a bumper, giving the ball a speed of 4. 5 m/s. If the ball has a mass of 50.0 g, what is the ball's kinetic energy in joules?

What explains the relationship among elements, compounds & mixtures

what noble gas electron configuration is achieved by the bromine atoms in a molecule of BR2, a diatomic element?

What are facts on osmosis?

If a map of temperature displayed stripes parallel to the equator with equal temperatures at equivalent distances north and south of the equator, it would mean that only blank affected temperature.

What is the term for the amount of salts in water? Evaporation Evaporation Salinity Thermocline Density

In an acid-base titration, of 20 ml of a m HCI solution with 1 m NaOH. How many ml of NaOH are needed