True or false If a material has a hardness of 8, it cannot be scratched by a material with a hardness of 7.

How did mendeleev arrange atoms in the periodic table?

How many moles of ammonia, NH3, can be made from 7.5 moles of H2? N2 + 3H2 → 2NH3 A. 15 moles B. 22 moles C. 5 moles

Compare the structure of the emulsifying agent to that of a soap. how are they similar?

The nucleus of an atom is a. the central core and is composed of protons and neutrons. b. positively charged and has more protons than neutrons. C. negatively charged and has a high density. d. negatively charged and has a low density.

Identify an ionic bond. identify an ionic bond. neutrons are lost. protons are pooled. electrons are transferred. protons are shared. electrons are gained.

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

Which of the following is not a source of air pollution related to human activities

Objects and substances in motion is I

If you were to remove an electron from a sodium atom that has eleven protons, what would be the electrical charge of the ion?

The atomic mass of fluorine in 19.0 amu, so the molar mass is?