Which elements would you use to predict the properties of Ekasilicon Why?

One such element gap, Mendeleev called ekasilicon. He predicted its mass, density, melting point and color based on its location in the periodic table. Fifteen years after this prediction, a new element was discovered in Germany and given the name Germanium. Its properties matched the properties of ekasilicon.

What atomic mass would you expect Ekasilicon to have and why?

If the atomic masses increase smoothly from left to right (about 3.3 units per atom), then ekaaluminum should have an atomic mass of about 68 u and ekasilicon should have an atomic mass of about 72 u. Germanium was isolated in 1886. Its atomic mass turned out to be 72.6 u.

Do elements have more in common with other elements that are in the same group period or both?

The elements of a group have similar chemical properties but in a period they have different chemical properties. … As in a group all elements have same no of valence electron that’s why they have similar chemical properties but in a period the no of valence electron varies that’s why they differ in chemical properties.

How did Moseley arrange the periodic table?

When Moseley arranged the elements in the periodic table by their number of protons rather than their atomic weights, the flaws in the periodic table that had been making scientists uncomfortable for decades simply disappeared.

What is the eka silicon?

Eka-silicon (germanium). Hence eka silicon is called germanium.

Who created the periodic table?

Dmitri Mendeleev

Albert Ghiorso

Periodic table/Inventors
In 1869, Russian chemist Dmitri Mendeleev created the framework that became the modern periodic table, leaving gaps for elements that were yet to be discovered. While arranging the elements according to their atomic weight, if he found that they did not fit into the group he would rearrange them.

How do alkaline earth metals differ from the alkali metals?

The key difference between alkali metals and alkaline earth metals is that all alkali metals have an electron in their outermost shell whereas all the alkaline earth metals have two outer electrons. … Their melting points are relatively lower than other metals.

What are Group 11 elements called?

The Group 11 is composed of copper (Cu), silver (Ag), and gold (Au). Silver and Au belong to the so-called noble metals. All these metals occur in variable oxidation stages, mainly +1, and +2, (Table II-11.1).

How many periods are in the periodic table?

seven
The periodic table of the elements contains all of the chemical elements that have been discovered or made; they are arranged, in the order of their atomic numbers, in seven horizontal periods, with the lanthanoids (lanthanum, 57, to lutetium, 71) and the actinoids (actinium, 89, to lawrencium, 103) indicated …

Who discovered oxygen?

Joseph Priestley

Antoine Lavoisier

Carl Wilhelm Scheele

Oxygen/Discoverers
When Joseph Priestley discovered oxygen in 1774, he answered age-old questions of why and how things burn.

Who named the elements?

Many countries have adopted the element names that have been agreed upon by the International Union of Pure and Applied Chemistry (IUPAC). According to the IUPAC, “elements can be named after a mythological concept, a mineral, a place or country, a property, or a scientist”.

What are the 7 families of the periodic table?

These families are alkali metals, alkaline earth metals, transition metals, post-transition metals, metalloids, halogens, noble metals, and noble gases. Many of these families belong to a single group on the periodic table.

What is the period of neon?

2
Fact box
Group 18 Melting point
Period 2 Boiling point
Block p Density (g cm−3)
Atomic number 10 Relative atomic mass
State at 20°C Gas Key isotopes

Which element is in period 2?

The second period contains the elements lithium, beryllium, boron, carbon, nitrogen, oxygen, fluorine, and neon. In a quantum mechanical description of atomic structure, this period corresponds to the filling of the second (n = 2) shell, more specifically its 2s and 2p subshells.

What are the 4 chemical families?

Families in the periodic table
  • The IA family is made up of the alkali metals. In reactions, these elements all tend to lose a single electron. …
  • The IIA family is made up of the alkaline earth metals. …
  • The VIIA family is made up of the halogens. …
  • The VIIIA family is made up of the noble gases.

What is the only metal that is liquid at room temperature?

Mercury
Mercury is the only metal that is liquid at normal temperatures.

What family does arsenic belong to?

phosphorus family
Arsenic is found in the fourth period/row of the table of elements. It is a member of the phosphorus family with other elements including phosphorus (duh), antimony (Sb), and bismuth (Bi).

What are the two most common alkaline earth metals?

Magnesium and calcium, particularly the latter, are abundant in nature (they are among the six most common elements on Earth) and play significant roles in geological and biological processes. Radium is a rare element, and all its isotopes are radioactive.

What chemical family is chlorine in?

Halogen

Nonmetal

Period 3 element

Chlorine/Chemical series

Is arsenic a poison?

Arsenic is highly toxic in its inorganic form. Contaminated water used for drinking, food preparation and irrigation of food crops poses the greatest threat to public health from arsenic. Long-term exposure to arsenic from drinking-water and food can cause cancer and skin lesions.

Which form of arsenic is more toxic?

Arsine gas is the most toxic form of arsenic. Inhalation of over 10 ppm is lethal and at concentrations higher than 25 ppm are reported to be lethal in less than an hour after exposure., while over 250ppm is reported to be instantaneously lethal.

Do humans need arsenic?

It seems that arsenic has a role in the metabolism of the amino acid methionine and in gene silencing (Uthus, 2003). … The recommended dose of selenium is 40 μg per day, whereas extrapolations from mammalian studies suggest that humans might need between 12.5 μg and 25 μg of arsenic.