What is the neutral atom that has its first two energy levels filled, has 7 electrons in its third energy level, and has no other electrons

What is the most common form of matter in the universe

Which of the following is not a characteristic of a hydrogen bond? 1. it is responsible for the unusual physical properties of water. 2. it is weaker than a covalent bond. 3. it is stronger than other dipole-dipole interactions. 4. it can occur when hydrogen is covalently bound to very electronegative elements liks f, cl, br and i.

What is the relative mass of an electron? a) 1/1840 the mass of a neutron + proton b) 1/1840 the mass of an alpha particle c) 1/1840 the mass of a c-12 atom d) 1/1840 the mass of a hydrogen atom