What is the correct answer?

What characteristics do the elements in a group share? In a period, share?

Katyanochek1 [597]

Answer:

The elements in same period have same principle quantum number or energy shell.

The elements in same group shows similar chemical and properties.

Explanation:

Inn group:

The elements in same group i.e present in vertical column shows similar chemical properties.

The elements in same group having same number of valance electrons. while in chemical reaction bonds are break and formed and valance electrons are involved. That's why elements in same group having same number of valance electrons and shows similar chemical properties.

In period:

While as we move from left to right the number of valance electron increase by one in every element. But the electron is added in same shell which means that their physical and chemical properties are different but principal quantum number is same.

3 0

2 years ago

In the laboratory, a general chemistry student measured the pH of a 0.529 M aqueous solution of phenol (a weak acid), C6H5OH to

Artyom0805 [142]

Answer:

The dissociation constant of phenol from given information is $9.34\times 10^{-11}$ .

Explanation:

The measured pH of the solution = 5.153

$C_6H_5OH\rightarrow C_6H_5O^-+H^+$

Initially c

At eq'm c-x x x

The expression of dissociation constant is given as:

$K_a=\frac{[C_6H_5O^-][H^+]}{[C_6H_5OOH]}$

Concentration of phenoxide ions and hydrogen ions are equal to x.

$pH=-\log[x]$

$5.153=-\log[x]$

$x=7.03\times 10^{-6} M$

$K_a=\frac{x\times x}{(c-x)}=\frac{x^2}{(c-x)}=\frac{(7.03\times 10^{-6} M)^2}{ 0.529 M-7.03\times 10^{-6} M}$

$K_a=9.34\times 10^{-11}$

The dissociation constant of phenol from given information is $9.34\times 10^{-11}$ .

4 0

3 years ago

If the dosage for a medication is 225mg/lb, how many grams should a 25-lb child be given?

Oksanka [162]

Answer:

5.625 grams

Explanation:

Start your equation with what you have been given. Place the units you need in your answer on the right side of the equal sign.

225mg

----------- X ----------- X ------------- = ? g

lb

Now start to fill in your equation and use a conversions to get rid of the units you don't want. Convert mg into grams first. The child's weight (25 lb) is placed over 1 just to get the equation lined up properly so you can see how the units cancel out.

225 mg 1 g 25 lb 5.625 g

--------------- X --------------- X ------------- = ---------------

lb 1000 mg 1 1

The lb on the top and bottom cancel each other out and you are left with just grams. Even though it is over one, that is the same at just 5.625 grams.

3 0

2 years ago

What is the mass of one atom of gold

bulgar [2K]

197 grams is the mass of one atom of gold

3 0

2 years ago

Read 2 more answers

Which is being developed by chemists to supplement fossils fuels?

MaRussiya [10]

Answer:

bio diesel