II. Chapter 2 - Atoms, Molecules, and lons Note: there are 28 problems total-you
ID: 1042543 • Letter: I
Question
II. Chapter 2 - Atoms, Molecules, and lons Note: there are 28 problems total-you are obligated to do 14 problems tota!! You are welcome to do additional problems for extra credit- all problems are worth 1 point each!!! a) Qualitative Section (you must do 3 problems each) 1. In regard to chemical compounds, what is the law of definite proportion? 2. What is an atom's nucleus comprised of and give a brief description of each? 3. Label what the arrows are referring to for sodium (Na) and give a brief a description of each Na 4. The forces that hold atoms together in compounds are called what? 5. What is a covalent bond? 6. What is an ionic bond? b) Quantitative Section (you must do 4 problems in this section)Explanation / Answer
a. 1. The law of definite proportion states that a given chemical compound always contains the same elements in the exact same proportions by mass of elements. in other words, it can be defined as 'a chemical compound is always made up of the exact same proportion of elements by mass.'
2. The nucleus of an atom is composed of protons and neutrons. All the mass of an atom is concentrated in the nucleus of it. Protons and neutrons are the fundamental particles of an atom. Protons are positive charge species while neutrons are neutral in nature. The no. of protons is always same as the no. of electrons present in it. The sum of the number of protons and neutrons is called atomic mass number.
3. 1123Na in this representation
Na stands for an element.
11 stands for the atomic number of an element here sodium.
23 stands for the atomic mass number of an element here sodium.
4. The coulombic force of attraction and repulsion holds the atoms in a compound together.
5. The type of bond which is formed between the atoms of same and different elements by sharing of the electrons of it. Covalent bond may be single, double and triple depending on the number of the shared pair of electrons. example- CH4 , four electrons of carbon form bond with a single electron of each hydrogen by means of sharing.
6. An ionic bond is formed by the transfer of electrons from one atom to the other atom by means of getting stability through electrostatic force of attraction. example - NaCl consists of Na+ and Cl- ions together by force of attraction.