Answer:
See detailed answer with explanation below.
Explanation:
Valence electrons are electrons found on the outermost shell of an atom. They are the electrons in an atom that participate in chemical combination. Recall that the outermost shell of an atom is also referred to as its valence shell. Let us consider an example; if we look at the atom, sodium-11, its electronic configuration is 2,8,1. The last one electron is the valence electron of sodium which is found in its outermost or valence shell.
Positive ions are formed when electrons are lost from the valence shell of an atom. For instance, if the outermost electron in sodium is lost, we now form the sodium ion Na^+ which is a positive ion. Positive ions possess less number of electrons compared to their corresponding atoms.
Negative ions are formed when one or more electrons is added to the valence shell of an atom. A negative ion possesses more electrons than its corresponding atom. For example, chlorine(Cl) contains 17 electrons but the chloride ion (Cl^-) contains 18 electrons.
In molecular compounds, a bond is formed when two electrons are shared between the bonding atoms. Each bonding atom may contribute one of the shared electrons (ordinary covalent bond) or one of the bonding atoms may provide the both shared electrons (coordinate covalent bond). The shared pair may be located at an equidistant position to the nucleus of both atoms. Similarly, the electron may be drawn closer to the nucleus of one atom than the other (polar covalent bond) depending on the electro negativity of the two bonding atoms.
The electrons are shared in order to complete the octet of each atom by so doing, the both bonding atoms now obey the octet rule. For example, two chlorine atoms may come together to form a covalent bond in which each chlorine atom has an octet of electrons on its outermost shell.
I just took a test with this question and got the answer wrong for saying ethane. The correct answer is propane.
Explanation:
8935200 mins plzzzźzzz mark it brainest
Answer:
I would say that it is the bond called complementary hydrogen bonds
Explanation:
The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three. The hydrogen bonding between complementary bases holds the two strands of DNA together.
Answer:
68.3%
Explanation:
First, let us look at the equation of reaction involving silver and magnesium chloride:
2Ag + MgCl2 ----> 2AgCl + Mg
1 mole of MgCl2 is required to precipitate 2 moles of Ag completely from the solution. That is a ratio of 1 to 2.
Now, mole of MgCl2 used to precipitate all the Ag
= molarity x volume
= 2.19 M x 2.89/1000
= 0.0063291 mole
Since 1 mole of MgCl2 would always require 2 moles of Ag, 0.0063291 mole will therefore require:
0.0063291 x 2 = 0.0126 mole of Ag
This means that 0.0126 mole of Ag is present in stephanie.
Mass of silver in stephanie = mole x molar mass
= 0.0126 x 107.8682
= 1.365 g
Thus, 1.365 g of silver is present in 2.00 g sample of stephanie.
Mass percent of silver in stephanie = 1.365/2.00 x 100
= 68.25% = 68.3% to the correct number of significant figure.
