Inorganic Chemistry
1. A subatomic particle with a single positive electrical charge is protons.
2. A subatomic particle with a single negative electrical charge is electrons.
3. A subatomic particle which is electrically neutral is neutrons.
4. The nucleus of an atom is made up of _protons_ and _neutrons.
5. The number of electrons forming a charge cloud around the nucleus is (pick one of the following) greater than; equal to; smaller than the number of protons in the nucleus of the atom.
6. The atomic number of potassium (3919K) is_19_. This means that a potassium atom has _19 protons and 19_ electrons.
7. What is the atomic mass of K? ___39________.
8. The atomic mass represents the number of _protons_ and _neutrons.
9. The
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Match the descriptions with the types of bonds listed (Covalent; Hydrogen; Ionic)
a. atoms lose electrons if they have just one or two electrons in their valence shells; they gain electrons if they need just one or two electrons to complete the valence shell as in K+CL- __Ionic bonds_
b. This bond is bridge-like; weak link between a hydrogen atom and another atom such as oxygen or nitrogen __hydrogen bond__
c. a pair of electrons is shared in this type of bond __covalent__
22. The atoms of water have (polar covalent; nonpolar covalent; ionic) bonds
Polar covalent and nonpolar covalent
23. As a result of the water molecule bond, each (hydrogen; oxygen) has a slightly negative charge and each (hydrogen; oxygen) has a slightly positive charge.
Oxygen and Hydrogen.
24. Hydrogen bonds contribute to a property of water called cohesion or the tendency of water molecules to stick together.
25. What do we call water when other substances (solutes) dissolve in it? Polar Covalent.
26. What special bond (in water) opposes water’s molecular movement when water absorbs energy requiring water to have more heat added to raise its temperature? Hydrogen Bond.
27. Which pH is most acid (4; 7; 10)
4
28. Which pH has the highest concentration of OH- ions? (4; 7; 10)
10
29. Which solution has a pH closest to neutral? (Stomach acid; blood; lemon juice; soap, household bleach)
Stomach acid
30. Pairs of weak acids and
The bent geometry of water molecule gives a slight overall negative charge to the side of the oxygen atom and a slight overall positive charge to the side of the hydrogen atom. This slight separation of charge gives the entire molecule an electrical polarity so water molecules are dipolar.
It is the radioactive isotope of potassium amongst the three isotopes where K-39 and K-41 are stable.
A. The electrons can be equally shared (covalent bond) or one atom can provide all of the electrons shared in the bond. The latter is called
The main component that make up an atom are protons, electrons and neutrons. Protons are positively charged. While electrons are negatively charged. Neutron is not like a proton or an electron. It isn't like proton or an electron because a neutron does not have a charge. They are arranged by the atomic number. The atomic number is the number of protons in the nucleus of an atom and the electrons are arranged in levels. The atomic number is the small number that is at the top left corner of the element in the box. Copper has twenty nine electrons and twenty nine protons. Copper has two isotopes. Which are copper 63 and copper 65. Their compositions of copper 63 and 65 are stable. The abundances of copper 63 is 69.15 percent and copper 65 is
of water molecules a very small number will have dissociated to form hydrogen (H+) and hydroxide (OH-) ions:
An important feature of water is its polar nature. A single water molecule consists of two hydrogen atoms and an oxygen atom (Henry Cavendish, 1782) (Gay-Lussac and Humboldt, 1805) [1] [3], however the electrons in the covalent bonding are not shared equally. Since oxygen has a greater electronegativity than hydrogen, the side of the molecule with the oxygen atom has a partial negative charge. This attraction is known as hydrogen bonding, explaining several properties of water. The hydrogen bonding is relatively weak in comparison to the covalent bond within the molecule itself, therefore is responsible for many of water’s physical properties [2]. Example of one such property is its high melting and boiling points as more heat is required to break the hydrogen bonds between molecules.
Hydrogen bonding is the electrostatic attraction between polar groups that occurs when a hydrogen atom bound to a highly electronegative atom such as nitrogen, oxygen, or fluorine experiences attraction to some other nearby highly electronegative atom. In the first lab, the paperclip floated on the surface of the water, without sinking. This was caused because of hydrogen bonding and surface tension. H2O (water) is a hydrogen bond, and it became attracted to other hydrogen bonds that were present in the beaker as well. Because the bonds became attracted to each other they created surface tension, where the water molecules, also known as polar molecules (since water is polar) are holding tight enough to support the paperclip. However, when soap was put into the water, it disrupted the order of the water molecules. Originally, when the molecules were holding the paperclip, their negative and positive charges were packed together next to each of their opposite charges. Soap being added, disrupted the order of the water
Because protons have a charge of +1, and electron have a charge of -1, an atom has an equal number of protons and electrons, making it electrically neutral. Atoms can lose or gain electrons, however, to gain a full valence (outer shell) of electrons. When this happens the atom becomes an ion, and it is no longer electrically neutral. As the element of an atom is governed by the number of protons in the nucleus, the ion is still the same element as the atom it came from.
Water has known properties which allow it to be versatile. Water has polarity, which is the phenomenon of
Water is a polar molecule, meaning that it has a positive and a negative pole. This is due to the fact that the water is an oxygen atom covalently bonded to 2 separate
Water is a substance that is composed of the chemical elements hydrogen and oxygen. A molecule consists of two hydrogen atoms, each linked by a single covalent bond to an oxygen atom. However, only two of the six outer-shell electrons of oxygen are used for this purpose, leaving four electrons which are organized into two non-bonding pairs. These pairs surrounding the oxygen have a partially negative charge mainly through electrostatic attraction increasing its electronegativity, which tend to arrange themselves as far from each other as possible in order to minimize repulsions. In turn, makes the hydrogen atoms to have a partially positive charge, and therefore making the two non-bonding pairs remain closer to the oxygen atom, which exert a stronger repulsion against the two covalent bonding pairs, effectively pushing the two hydrogen atoms closer together. This electronic structure of water makes it possible for the molecule to bend on a special way, shown through the figure:
Coulomb forces, or as they are commonly called, electrostatic forces, are forces acting between two points of charges in which two like or opposite charges will respectively repel or attract each other along a straight line in order to join or part their centers (Britannica). These electrostatic forces can also act between polarized molecules, leading to so called “dipole-dipole interactions”, a force of attraction acting between two poles of separate compounds. In order to overcome this force of attraction energy would be needed, which is why the state of matter of a compound changes as the temperature increases. The temperature is the kinetic force that overcomes the intermolecular force acting between different molecules, thus meaning that compounds with a stronger intermolecular force requires more kinetic energy to change state. In figure 2A we see two polarized molecules of BrCl interacting with each other in a normal dipole-dipole interaction. This weak force of attraction is what holds BrCl together in the solid and liquid phase, giving it a boiling point of 278
slightly negative charged on the O atom ~ partially negative (δ-) slightly positive charged on both H atoms ~ partially positive
By sharing electrons, atoms within a molecule that are attracted to one another is called an intramolecular force. Between the molecules intermolecular force, the physical properties for example the melting points and boiling points, relate to the solubility and the strength of these force.
The most important substance in the world is water, without it there would be no world. Water is a molecule that is composed of two hydrogen atoms and one oxygen atom, also known as H2O. Water is a polar molecule, making it able to dissolve other polar molecules. Water is attracted to itself by cohesion. Cohesion is the attraction of one substance to itself. Cohesion is possible for water due to its strong hydrogen bonds. Alone hydrogen bonds are weak, but together they form one of the strongest bonds known. Water is an extremely diverse substance that can be in solid form, liquid form, and gas form. The normal temperature of water is 25oC, which produces its liquid form. When water reaches below 0oC, it freezes and becomes solid. Above100oC is when water reaches its gaseous form and boiling point; that is more than a 75o temperature change from liquid to gas. Studies show that the evaporation rate of a liquid depends on the