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4 years ago

How do you tell by the formula that an element on the periodic table is a metal

1 answer:

7 0

The metalloids are on the right side of the periodic table B, Si, Ge, As, Sb, Te, and At. The nonmetals are also on the right side next to the metalloids, there should be a He at the top right of the periodic table and there should be one more nonmetal at the top left of the periodic table that is H. And from the metals they are all on the middle next to the metalloids, starting from Li, Be, Na, and Mg as so on all of those are metals.

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Explain how the atoms are held together by tge covalent bond in a molecule of hydrogen?

sveta [45]

Answer:

A hydrogen molecule forms from two hydrogen atoms, each with one electron in a 1 s orbital. The two hydrogen atoms are attracted to the same pair of electrons in the covalent bond. The bond is represented either as a pair of “dots” or as a solid line. Each hydrogen atom acquires a helium-like electron configuration. Shared electrons located in the space between the two nuclei are called bonding electrons. The bonded pair is the “glue” that holds the atoms together in molecular units. The hydrogen molecule is the simplest substance having a covalent bond.

Explanation:

6 0

2 years ago

Equation Unbalanced : __AlCl3 + __F2 --> __AlF3 + __Cl2

Greeley [361]

$\\ \rm\Rrightarrow 2AlCl_3+3F_2\longrightarrow 2AlF_3+3Cl_2$

Balanced

3mols of fluorine produce 2 mol chlorine

1 mol fluorine produces 2/3=0.6mol chlorine

Moles of fluorine gas=

4/19
0.2mol.approx

Moles of chlorine:-

0.2(0.6)=0.18mol

Mass of chlorine

71(0.18)
12.78g

6 0

3 years ago

What is Kb for N2H4 if the pH of a 0.158M solution of N2H5Cl is 4.5?

olasank [31]

Answer:

Kb $= 1.58 * 10^{-6}$

Explanation:

The correct question is

What is Kb for N2H4 if the pH of a 0.158M solution of N2H5Cl is 4.5?

Solution-

N2H4Cl hydrolyses on addition of water

The reaction equation is as follows -

N2H4+ + H2O ----> N2H4 + H3O+

$Ka = \frac{K_w}{K_b} = \frac{10^{-14}}{K_b}$

pH $= 4.5$

$[H+] = 10^{-pH} = 10^{-4.5}$

$K_b= \frac{10^{-14} }{K_b} = \frac{Y_2}{0.158} \\K_b= \frac{(10^{-4.5})^2}{0.158}\\=> Kb = 0.158 * 10-14 /(10-4.5)2$

Kb $= 1.58 * 10^{-6}$

3 0

3 years ago

#1: Which type of substance is an electron-pair donor?

Aneli [31]

Answer is: D. Lewis base.
Lewis acid is a chemical element, molecule or ion that contains an empty orbital which is capable of accepting an electron pair from a Lewis base. A Lewis base is element, molecule or ion that has a filled orbital and has electron pair which is not involved in bonding and can give it to Lewis acid. Lewis base is for example ammonia (NH3).

7 0

3 years ago

What is the mass of one mole of popcorn kernels? (sig fig hint: consider the precision of avogadro's number to determine the cor

svetlana [45]

Since the mass of a single popcorn kernel is not given, lets us assume that it is 1 gram

Now:

1 mole of popcorn kernels contain $6.023 * 10^{23}$ kernels