I believe it is either A. or C. my guess is A.
The correct option is B.
Mendeleev was the one who originated the idea of arranging elements in the periodic table according to their chemical and physical properties. He left spaces in the periodic table and predicted the discovery of those elements that had not been discovered then. One of these elements is Gallium. He predicted that gallium is going to be a metal and he gave the properties that the element will possess. He also predicted that the element gallium will be placed under aluminium in the periodic table.
Answer:
Explanation:
When potassium chloride reacts with lead acetate in aqueous medium, it gives white precipitate of lead chloride and potassium acetate in aqueous medium as a product.
As shown in chemical reaction given below:
EASY AS PIE AND I LIKE PIE
Calcium iodide (CaI2) is an ionic bond, which means that electrons are transferred. In order for Ca to become the ion Ca2+, the calcium atom must lose 2 electrons. (Electrons have a negative charge, so when an atom loses 2 electrons, its ion becomes more positive.) In order for I to become the ion I1−, the iodine atom must gain 1 electron. (When an atom gains an electron, its ion will be more negative.) However, the formula for calcium iodide is CaI2 - there are 2 iodine ions present. This makes sense because the iodine ion has a charge of -1, so two iodine ions have to be present to cancel out the +2 charge of the calcium ion. Therefore, the calcium atom transfers 2 valence electrons, one to each iodine atom, to form the ionic bond.
IF WRONG, SORRY
Answer:
Selenium
Explanation:
selenium has 4 energy levels (think a 4 story building) while oxygen only has 2 (think 2 story building). which one is taller?
