What is the total number of electrons needed to completely fill all of the orbitals in an atoms second principal energy level

If the first energy level can hold 2 electrons, the second holds 8, and the third can hold 8, what if the atomic number is bigger than 18? Where do the other electrons go?

Using the periodic table, choose the more reactive metal. (hint: reactivity of Ga > Al: reactivity of Zn > Ga) Pt or Ag

On a floor directly underneath a second-floor balcony, there are several spherical drops of blood about 6 mm in diameter. Which statement best accounts for the drops?

Calculate how many moles of pure CaCl2 are present in the 1.00 g of CaCl 2 ⋅ 2H 2 O

explain why the method of converting units that we've used all unit is called the "factor-label" method.

How many moles are in 25.2g of KMnO4?

Lewis diagram of Ozone

Name the feature of the ocean floor shown at A and describe how it's formed.

A certain element consists of two stable isotopes. The first has a mass of 62.9 amu and a percent natural abundance of 69.1 %. The second has a mass of 64.9 amu and a percent natural abundance of 30.9 %. What is the atomic weight of the element?

Nonmetals rarely lose electrons in chemical reactions because?