The Periodic Guide: Study Guide Essay examples

For the lesson observed the objectives was to explain the trends of the periodic table based on the elements’ valence electrons and atomic numbers. Additionally, students were responsible for applying their previous knowledge in calculating subatomic particles to review the Bohr Models and discus the relationship among families in the periodic table. Students will use the information from today’s lesson to make future judgments on reactivity and bonding created during chemical reactions in the next unit. Lastly, students were to connect the information on elemental properties to previous experiences with their health, commercial products, and everyday life.

Atoms of the same element can have different masses, this is called isotopes. After 200 years John Dalton discovery of the Dalton’s Atomic theory it is still used today John Dalton’s atomic theory is the foundation of which Chemistry was built on.

The history of the atomic theory is thoroughly extensive. It had all started around 400 BCE when few people believed in an atomic theory, that atoms are building blocks. Democratic believed matter was made up of tiny particles. He called them atomos. Democratic is Leucippus’ most infamous pupil Later in history, the law of definite proportions was discovered. Two samples of given compounds are made of the same elements in exactly same proportions by mass regardless of the size or sources of the samples. After this came the law of conservation of mass and law of multiple proportions. Around 1808, John Dalton came up with a different atomic theory. He used Greek concept of the atom and all of the laws previously mentioned to acquire his

James Dalton determined that elements exist as discrete packets of matter (Crash Course Video). Leucippus and Democritus composed the brilliant idea that all matter is composed of tiny uncuttable or “atomos” particles (Crash Course Video). There were many theories and discoveries on the knowledge of atoms in the past, some more known than others, like William Crookes (Crash Course Video and Atomic Structure Prezi).

Moseley determined that the number of protons was the basic difference between elements. This discovery proved the hypothesis of the atomic number and, therefore, helped to refine the order of elements in the periodic table. After rearranging the elements according to their atomic number rather than the atomic weights, fundamental flaws in the original periodic table were revealed. Henry Moseley 'came up with arranging elements according to proton number. ... Call the police, give the location, and tell them there is a person lying on the ground (or wherever they are) that appears to be dead. Because of Moseley's x-ray work, elements could be ordered in the periodic system in order of atomic number rather than atomic weight. There were two

The periodic table was a display of all known elements ordered in increasing atomic number. The modern periodic table has groups, a column of elements, and periods, a row of elements. Elements within the same group have similar chemical properties because they all possess the same amount of electrons in the highest occupied energy level, also known as valence electrons. Due to the fact that chemical properties are determined by electron configuration, elements in the same group will react similarly. This was because elements in the same group want to lose or gain the same amount of electrons, in order for them to become stable ions. For metals, the elements lose electrons in order to become stable ions and nonmetals gain electrons to become stable ions. All the elements in a group will

The Periodic Table is guidance or map to access different elements specific information, such as: atomic mass, isotopic richness, nuclear spins, electronic configuration and the position of elements belong to which group and period in table. Over the past decades there were many Scientifics which help to improvement of Periodic table but few of them made the most influence and contribution on Periodic table such as : Johann Dobereiner ,John Newlands , Dmitri Mendeleev and Henry Moseley.

Good morning class! Yesterday we finished reading the section on chemical bonding. It is important that you all understand the differences between the two major types of bonding, which are covalent and ionic bonding. Both forms have specific characteristics that are important to memorize for future topics we shall discuss in this class and in your college courses. In my opinion, the best way to learn and memorize different characteristics between two different things is by completing a Venn Diagram.

The manner in which the negative charge of an atom or a molecule is arranged in three-dimensional space is determined by the electronic charge density distribution. Thus, it determines directly the sizes and shapes of molecules, their electrical moments and, indeed, all of their chemical and physical

Throughout history the periodic table of elements has been influenced and amended by multiple scientists. These scientists include Johann Dobereiner, A.E Beguyer de Chancourtois, John Newlands, and Glenn Seaborg. As well as Dmitri Ivanovich Mendeleev and Lothar Meyer the creators of the periodic table. There are many ways that the periodic table of elements was set out. For example the table can be organized using patterns between atomic numbers, electronegativity, ionization energy, structure (gas or solid) valence electrons and electron configuration (shells) as seen in the modern day periodic table.

As we know, today there are one-hundred and eighteen elements on the periodic table of elements, but it didn’t start out like this. Robert Boyle, a scientist, discovered the element phosphorus in 1680. Also, in this year the element became known to the public. By the year of 1809, the number of elements discovered at the time was up to 47. Also, scientists began to see a pattern in the characteristics of the elements. Later in 1863, The 56 elements discovered at the time were then divided into 11 groups based on their characteristics by an english chemist named John Newlands. In the year 1869 a Russian chemist by the name of Dimitri Mendeleev started the making of the periodic table. He started by rearranging the elements in order of atomic mass. He also expected the discovery of other elements, so he decided to leave empty spaces in his table so he could add new elements later. In 1894, the noble gases were discovered by Sir William Ramsay and Lord Rayleigh. The noble gases were added to the periodic table in a group labeled 0. Eventually in 1945, Glenn Seaborg discovered and identified lanthanides and actinides. The Lanthanides were the elements with atomic numbers greater than 57 and lower than 71. The Actinides were elements greater than 92. These elements today are located underneath the periodic table (refer to figure 1). The last major change to the periodic table occurred in the 20th century due to the work of Glenn Seaborg. starting with his

Today, the periodic table is used by many people worldwide to learn more about the elements located on it. It has evolved into a much easier piece of information to use because of all the many scientists and chemists that have revised it over the last hundred ish years. There are certain things on the periodic table that help to learn more about each element. Periodic families are used to help understand similarities between the atomic structures of elements. Trends are used to show certain patterns within the periodic table. One can learn many things about the periodic table from studying it.

The atomic theory is a theory that has been worked on since 400 bc. For a while the theory was left untouched by the scientific community until 1803 when John Dalton stoked the fire of scientific discovery, with his clarification of elements and compounds being two different combinations of atoms. The theory was then untouched for 83 years when E. Goldstein revamped the scientific community’s

Sometimes this method of arranging elements meant there were gaps in his horizontal rows or 'periods'. But instead of seeing this as a problem, Mendeleev thought it simply meant that the elements which belonged in the gaps had not yet been discovered. He was also able to work out the atomic mass of the missing elements, and so predict their properties. And when they were discovered, Mendeleev turned out to be right. For example, he predicted the properties of an undiscovered element that should fit below aluminium in his table. When this element, called gallium, was discovered in 1875, its properties were found to be close to Mendeleev's predictions. Two other predicted elements were later discovered, lending further credit to Mendeleev's

Although Democritus had a nice idea, it was not enough for some scientists in the late 1700's. Scientists like Joseph Priestly, Antoine Lavoisier demonstrated that substances could combine to form new materials. Yet, it was John Dalton who combined these ideas. He worked with the pressures and weights of different gases, which led him to believe that their properties are dependent on atoms. He thought that atoms from different elements could combine to form the known elements. He was the first person to make an attempt in making a table of atomic weights, which was a giant leap towards the making of the future "Periodic Table" Dalton's atomic theory contains of five assumptions: