All categories

3 years ago

Help me please will mark brainliest

Chemistry

2 answers:

Ilya [14]3 years ago

4 0

Answer:

Explanation:

Period is horizontal group, so left to right it does increase. Down the side they are numbered 1-7 and depending on valence electrons they can have different properties

murzikaleks [220]3 years ago

4 0

Answer:

Explanation:

Im pretty sure it's A. I MIGHT be wrong so dont quote me on this. THis is what the internet says:

"Atomic Radius. Atomic radii decrease from left to right across a period and increase from top to bottom along a group."

You might be interested in

A mineral is discovered that cleaves in parallel pieces that look like pages from a book?

Dmitrij [34]

The mineral that you described is called Muscovite. The pages of the book description fits muscovite found in granite pegmatites where it is found in large crystals with a pseudohexagonal outline that are called "books".

5 0

3 years ago

At a wastewater treatment plant, FeCl3(s) is added to remove excess phosphate from the effluent. Assume the following reactions

RoseWind [281]

Answer : The concentration of $Fe^{3+}$ needed is, $2.37\times 10^4M$

Explanation :

First we have to calculate the mole of phosphate.

As we are given that, 1 mg P/L that means, 1 mg of phosphate present in 1 L of solution.

$\text{Moles of phosphate}=\frac{\text{Mass of phosphate}}{\text{Molar mass of phosphate}}$

Molar mass of phosphate = 94.97 g/mole

$\text{Moles of phosphate}=\frac{1mg}{94.97g/mol}=\frac{0.001g}{94.97g/mol}=1.053\times 10^{-5}mol$

Now we have to calculate the concentration of phosphate.

$\text{Concentration of phosphate}=\frac{\text{Moles of phosphate}}{\text{Volume of solution}}$

$\text{Concentration of phosphate}=\frac{1.053\times 10^{-5}mol}{1L}=1.053\times 10^{-5}mol/L$

Now we have to calculate the concentration of $Fe^{3+}$ .

The second equilibrium reaction is,

$FePO_4\rightleftharpoons Fe^{3+}+PO_4^{3-}$

The solubility constant expression for this reaction is:

$K_{sp}=[Fe^{3+}][PO_4^{3-}]$

Given: $K_{sp}=\frac{1}{4}$

$\frac{1}{4}=[Fe^{3+}]\times 1.053\times 10^{-5}mol/L$

$[Fe^{3+}]=2.37\times 10^4M$

Thus, the concentration of $Fe^{3+}$ needed is, $2.37\times 10^4M$

8 0

4 years ago

The solution you identified in question (1) acts as a buffer due to reactions that occur within the solution when an acid or a b

weeeeeb [17]

Answer:

The answer is " $\bold{CH_3COO^{-} \ (aq) + H^{+}\ (aq) \longrightarrow CH_3COOH \ (aq)}$ "

Explanation:

When $HCI$ is added in the chemical equation it reacts with sodium acetate so, it will give the following chemical equation:

$CH_3COONa\ (aq) + HCl\ (aq)\longrightarrow CH_3COOH\ (aq) + NaCl\ (aq)\\\\$

In this, the $CH_3COOH$ is a weak acid so, it not completely dissociated.

$CH_3COONa \ (aq) \ \ and \ NaCl$ were strong electrolytes they are completely dissociated.

The $HCl$ is a strong acid so, it is completely dissociated So, the net ionic equation is:

$CH_3COO^{-} \ (aq) + H^{+}\ (aq) \longrightarrow CH_3COOH \ (aq)$

8 0

3 years ago

Why is having a healthy lion population in an African savanna important for maintaining biodiversity in that ecosystem?

scoundrel [369]

Answer:c

Explanation:

3 0

3 years ago

What happens to the number pf protons in an atom as you move across a period.

sineoko [7]

Answer:

A. The number of protons increase.

Explanation:

Each element rank is determined by the number of protons.

Hydrogen is #1 with 1 proton, Helium is #2 with 2 protons, Lithium is #3 with 3 protons, and so on.

6 0

4 years ago

Help me please will mark brainliest ​

Help me please will mark brainliest