All categories

3 years ago

How does the periodic table arrange element's atomic number?

Chemistry

1 answer:

Dmitry [639]3 years ago

7 0

Answer:

The periodic table of elements arranges all of the known chemical elements in an informative array. Elements are arranged from left to right and top to bottom in order of increasing atomic number. Order generally coincides with increasing atomic mass. The rows are called periods.

You might be interested in

A volume of 25cm3 of a carbonate solution of concentration 0.2mol dm-3 was neutralized by 20 cm3 of acid of concentration 0.5 mo

Galina-37 [17]

Answer: 1 mol of carbonate to 2 mol of acid

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Molarity of the solution}=\frac{\text{Moles of solute}\times 1000}{\text{Volume of solution in ml}}$

a) $\text{Moles of carbonate}=\frac{0.2moldm^{-3}\times 25cm^3}{1000}=0.005mol$

b) $\text{Moles of acid}=\frac{0.5moldm^{-3}\times 20cm^3}{1000}=0.01mol$

Thus the mole ratio of carbonate to acid is = $\frac{0.005}{0.01}=\frac{1}{2}$

7 0

3 years ago

When electrons have moved from one element to another, what type of bond has formed?

aliya0001 [1]

A covenant bond is formed when electrons move from one element to another.

3 0

3 years ago

Calculate the standard cell potential (E∘) for the reaction X(s)+Y+(aq)→X+(aq)+Y(s) if K = 8.97×10−3. Express your answer to thr

puteri [66]

Answer: The standard cell potential (E∘) for the reaction $X(s)+Y^+(aq)\rightarrow X^+(aq)+Y(s)$ is -0.121 V

Explanation:

The reaction is:

$X(s)+Y^+(aq)\rightarrow X^+(aq)+Y(s)$

Relation between standard Gibbs free energy and equilibrium constant follows:

$\Delta G^o=-RT\ln K$

where,

$\Delta G^o$ = Standard Gibbs free energy = ?

R = Gas constant = $8.314J/K mol$

T = temperature = 298 K

K= equilibrium constant = $8.97\times 10^{-3}$

Putting values in above equation, we get:

$\Delta G^0=-(8.314J/Kmol\times 298K\times \ln (8.97\times 10^{-3})\\\\\Delta G^0=11678.9J/mol$

To calculate standard Gibbs free energy, we use the equation:

$\Delta G^o=-nFE^o_{cell}$

Where,

n = number of electrons transferred = 1

F = Faradays constant = 96500 C

$E^o_{cell}$ = standard cell potential = ?

Putting values in above equation, we get:

$11678.9J/mol=-1\times 96500\times E^0_{cell}$

$\frac{11678.9J/mol}{-96500}=E^0_{cell}$

$-0.121V=E^0_{cell}$

Thus standard cell potential (E∘) for the reaction $X(s)+Y^+(aq)\rightarrow X^+(aq)+Y(s)$ is -0.121 V

5 0

4 years ago

a 0.784 g sample of magnesium is added to a 250 ml flask and dissolved in 150ml of water. magnesium hydroxide obtained from the

Svetach [21]

The chemical reaction involving Mg(OH)2 and HCl is:

Mg(OH)2 + 2HCl --> MgCl2 + 2H2O

So we see that for every 2 moles of HCl, 1 mole of Mg is reacted.

Calculating for moles HCl:

moles HCl = 0.300 M * 0.215 L

moles HCl = 0.0645 mol

The moles Mg then is:

moles Mg = 0.0645 mol * (1 / 2)

moles Mg = 0.03225 mol

5 0

3 years ago

А. B Which of the following is true about the picture above? What would it be?

JulijaS [17]

Answer:

Container A is a solution and Container B is a colloid.

Explanation:

Container A is a solution as the tyndall efffect is not present. You cannot see the light bean through the glass.

Container B is a suspension or a colloid as you can see the beam through the glass.

The first option proposes Container A is a colloid...this is not correct

The third option is not true as the tyndall effect is only displayed in container B

The fourth option is not correct the tyndall effect is not present in container A meaning it would not be a suspension or a colloid and you can see the tyndall effect in container B indicating its not a solution

8 0

4 years ago