The mass number of an atom of an element is 55. The number of neutrons in it is 5 times greater than the atomic number. How many protons, neutrons and electrons are in this atom? What element does this atom represent?

Which sentence about particles in matter is true? a. atoms are present in solids and liquids but not in gases. b. the particles of matter are in constant motion. c. the same kinds of atoms are found in different elements. d. when a solid changes to a liquid, the sizes of the particles change.

When did stem cell research become known ? who discovered stem cell? what experiments or studies have been conducted so far?

Determine type of reaction & predict the product c3h12+o2 =