Chemistry Unit 1,2,3 Test

What is chemistry?

Bucky balls are carbon lattice structures that contain [blank_start]______[blank_end] carbons.

The IUPAC is an organization that regulates the physical laws of chemistry.

Chemistry is the study of [blank_start]_________[blank_end] and its interactions.

Around [blank_start]_______[blank_end], early Greek philosophers argued that [blank_start]_________[blank_end] could be subdivided into tiny indivisible particles called [blank_start]_________[blank_end].

Democritus stated that atoms have different sizes, are never in motion and are separated by empty space.

In around the 17th century, alchemists explored the nature of matter intensely. They searched for exclusive prizes such as the alchemy of life.

Dalton proposed that... - all mater is made up of tiny [blank_start]indivisible particles[blank_end] called [blank_start]atoms[blank_end] - all atoms of the of an element are [blank_start]identical[blank_end] - atoms of different elements are [blank_start]different[blank_end] - atoms are rearranged from [blank_start]new substances[blank_end] in chemical reactions, but they are never created nor [blank_start]destroyed[blank_end].

Thompson created the [blank_start]plum pudding model[blank_end] from his experiment with a cathode ray and as a result discovered [blank_start]electrons[blank_end]. Ernest Rutherford performed the [blank_start]gold foil experiment[blank_end] and from this he deduced that there was a [blank_start]positively charged nucleus[blank_end]. Chadwick discovered the [blank_start]neutral neutron[blank_end] and Bohr proposed energy levels from his observation of photon emission.

Bohr Rutherford diagrams look as follows.

Z represents the [blank_start]atomic number[blank_end]. A represents the [blank_start]atomic mass[blank_end]. X represents the [blank_start]element symbol[blank_end].

Valence electron are electron on the second outermost shell.

All atoms are in the search of a full octet to some extent.

Noble gases are highly reactive as they constantly search to fill their octet.

Ions are formed when...

Positive ions are [blank_start]cations[blank_end] and negative ions are [blank_start]anions[blank_end].

Anions and Cations come together to form a molecular compound.

Element with multiple ion charges...

Polyatomic ions are ions that consist of more than one atom.

Magnesium ion [blank_start]Na^(2+)[blank_end], Sodium ion [blank_start]Na^(+)[blank_end], Ammonium [blank_start]NH4^(+)[blank_end], Sulphate [blank_start]SO4^(2-)[blank_end], Chlorate [blank_start]ClO3^(-)[blank_end], Carbonate [blank_start]CO3^(2-)[blank_end], Phosphate [blank_start]PO4^(3-)[blank_end], Cyanide [blank_start]CN^(-)[blank_end], Hydroxide [blank_start]OH^(-)[blank_end], Bicarbonate [blank_start]HCO3^(-)[blank_end], Nitrate [blank_start]NO3^(-)[blank_end]

99% of the human body is made of only 6 elements (oxygen, carbon, hydrogen, nitrogen, calcium and phosphorus).

Isotopes are atoms of the same element that have different numbers of protons.

How are isotopes distinguished?

Isotopic abundance is the percentage of an isotope in a sample of an element.

What do scientists use to find the isotopic abundance of a given isotope?

Alpha particles have the same structure as a [blank_start]helium atom nucleus[blank_end] and can be blocked by [blank_start]paper[blank_end]. Beta particles are [blank_start]negatively charged electrons[blank_end] that can pass through paper but not through [blank_start]aluminium[blank_end]. [blank_start]Gamma rays[blank_end] are a high-energy electromagnetic radiation but it cannot pass through [blank_start]lead[blank_end].

Radioactive isotopes are isotopes that decay to form nuclear radiation.

Element X has isotopes X-200 (80%) and X-201(20%),. Calculate the atomic mass of element X.[blank_start]________[blank_end] amu

The periodic table contains almost all of the known elements.

Hydrogen does not belong to a specific group of elements as it is an exception.

What are the properties of alkali metals?

Transition metals are the metals that are found near the center of the periodic table. They are strong , hard metals with high melting points as well as good conductors of electricity. Many react with oxygen to form oxides. Some are multivalent.

Metalloids are found along the staircase.

Transuranic metals are those that have an atomic number greater then [blank_start]_________[blank_end].

Noble gases are gases at room temperature with high melting and boiling points. They are extremely unreactive.

Halogens may be solid liquid or gas at room temperatures and are extremely reactive. They also exhibit non-metallic properties such as no lustre and non-conduction.