Chemistry Review - Tagged

CHEMISTRY REVIEW Please read the chapter on Chemistry/slides/notes and focus on the following: definitions of atom, molecule, compound, ion most common elements in living organisms atom structure and subatomic particles atomic number, mass number, atomic mass definitions covalent bond-polar vs nonpolar - electronegativity ionic bond hydrogen bond van der Waals Complete the following fill in the blank: 1. Atoms are the smallest units of matter. 2. 96% of our body is made up of just_Four_ (number) elements. These are_oxygen (O), carbon (C), hydrogen (H), and nitrogen (N). 3. An atom is made of_three_(number) subatomic particles: _neutrons, protons, and electrons. 4. The number of_protons_ is called the atomic number, and it is unique for each element. 5. Mass number is the sum of_protons_and_neutrons. Atomic mass has the same value as mass number, but it is measured in_daltons_. 6. A compound is made of two or more_different elements. Oxygen, or hydrogen, or nitrogen, found in the air, are not compounds, they are_elements_. 7. Isotopes are different versions of a common element. They differ in the number of neutrons_. 8. Carbon-14 is an isotope of the common form of carbon, Carbon -12. C-14 has 2 more _neutrons than C-12. 9. A covalent bond is formed by sharing of electrons between two atoms. A single covalent bond consists of one pair of electrons, whereas a double covalent bond consists of two _pairs of electrons. 10. The covalent bond between O and His_polar. It is called that, because the sharing of electrons between the O and H is NOT equal. O is more_electronegative than H, which means that it pulls electrons more strongly. This results in O having partial_negative_ charge, and H having partial_positive charge. 11. A covalent bond between C and H is_nonpolar_. It is called that, because electrons are shared_equally between these two atoms. C and H, are not _electronegative_. 12. Anionic bond is formed when an electron is transferred from one atom to another. The atom that loses an electron is called a(n) _cation and has _ positive_ charge. The atom that gains an electron is called a(n) _ anion and has _negative_ charge. atom 13. A hydrogen bond is formed between a H in one molecule and an electronegative in another molecule. The H can make an H-bond only if it is found in a_polar covalent bond, in its own molecule. 14. H-bonds give_water_ many of its special properties. 15. A van der Waals interaction is the_weak type of bond. All molecules form these bonds. These interactions become important when found in great numbers. The often help the 3D shape of large molecules such as_dna_or_protein