Answer:
B. Catalyst B
Explanation:
Explanation: Enzymes are complex proteins that have a very specific shape. Just as a key fits a lock and allows it to open, the active site of the enzyme fits the reactants, allowing them to meet at the right orientation to form new chemical bonds. The shape of catalyst B is the best fit to the given reactants and product. The presence of catalysts allows reactions to proceed at much lower energy levels than without, as high-energy collisions between molecules are no longer necessary.
B) metals are found on the left side of the periodic table.
C) rare earth elements are in the first column, on the left.
D) transition metals are in the center of the periodic table.
Answer: C) rare earth elements are in the first column, on the left.
Explanation:
In fact, rare earth elements are in the third column, on the left.
The periodic table of the elements is an arrangement of the chemical elements in the form of a table, ordered by their atomic number (number of protons), by their configuration of electrons and their chemical properties. It was progressively developed over time as the scientific knowledge advanced; for this reason many modifications and corrections might be done in the future.
This table is divided into rows and columns, which represent the periods and groups or families. For its location the atomic number and valence of each element was considered.
In this sense, the elements in the periodic table are mainly arranged as follows:
-Alkali metals and Alkaline Earth metals in the first two columns, on the left.
-Rare earth elements in the third column (rows 6 and 7), on the left.
-Transition metals in the center.
-Basic metals and semi-metals to the right
-Non-metals to the right (and Hidrogen in the first row and column)
-Noble gases (or inert gases) farthest to the right.
Answer: The correct answer is Option C.
Explanation:
Elements are divided into 7 Periods and 18 Groups in a periodic table.
Metals are present on the left side of the periodic table. They are present from Group 1 to Group 14 of the periodic table.
Non-metals are present on right side of the periodic table. They are present from group 15 to group 17 of the periodic table.
Inert gases are present in the farthermost right side of the periodic table. They are present in group 18.
Transition metals are present in the center of the periodic table from group 3 to group 12.
Rare earth metals are present in group 3 from the left. All the elements present in lanthanides series are considered as rare Earth metals.
Hence, the correct answer is Option C.
Answer: The given statement is false.
Explanation:
When there is more difference in the ratio or number of protons and neutrons then nucleus of the atom becomes unstable in nature. This unstability is caused due to greater repulsion between the like charges of sub-atomic particles.
As a result, this force of repulsion becomes greater than the binding energy. And, this force is known as the weak force because it is unable to bind the neutrons and protons together.
The proton and neutron ratio for smaller elements is 1:1 and for higher elements it has to be 1:5. Since, is a smaller element with 4 protons and 4 neutrons. Hence, the proton and neutron ratio is 1:1.
Therefore, is stable in nature.
Thus, we can conclude that the statement nucleus of 8Be, which consists of four protons and four neutrons, is very unstable and spontaneously breaks into two alpha particles (helium nuclei, each consisting of two protons and two neutrons), is false.
The correct option is D.
Another way to write the chemical formula of magnesium phosphite is Mg3O6P2. The compound is made up of three atoms of magnesium, six atoms of oxygen and two atoms of phosphorus. The compound has anti fungal properties and it is also used as fertilizer. The compound is partially soluble in waster and it can be yellow or green in color.
Answer: I think the answer is 40.45 please let me know if it's wrong
A. Ar
B. CO
C. CO2
D. NaCl