The nucleus is:

a. the center of an atom

c. specified by mass number

b. specified by atomic number

d. all of the above

Nitrogen atom in ammonia has four identical orbitals in the shape of a pyramid or tetrahedron. Draw an energy level diagram to show the formation of these hybrid orbitals.

When choosing a suitable indicator for a titration between a strong acid and a weak base, the indicator should change color in the pH range of: exactly 7 less than 7 (slightly acidic) greater than 7 (slightly basic) near 14 (very basic)

How many g of MgCO3 (s) are needed to make 1.2 L of 1.5 M MgCl2 (aq) solution?

Which of CO O2 CH3CI PF3 is nonpolar

A group of students want to see how temperature affects the time spilled water to dry up what will be independent and dependent variable

Which is a pure substance A) mixture B) solution C) element

Samuel adds a teaspoon of salt to a glass of water. He notices that the song disappears. Samuel takes a sip to discover that the water taste salty. What kind of change has occurred?

How are the physical and chemical properties of atoms represented on the periodic table of elements

how do we know isotopes exist?

Is albinism a dominant or recessive trait