All categories

3 years ago

What do the numbers listed for an element on the periodic table represent?

Chemistry

2 answers:

Anna007 [38]3 years ago

8 0

The smaller number is the number of protons, and the greater number is the mass.

almond37 [142]3 years ago

8 0

The smaller number is protons and the greater number is the mass. If you subtract the larger number from the smaller it can show you how many neutrons there is it that element

You might be interested in

A chemist needs 0.550 mol selenium for a reaction. What mass of selenium should a chemist use?

-BARSIC- [3]

Answer:

The chemist would require to use 43.43 grams.

Explanation:

In order to solve this problem we need to know<u> how much do 0.550 moles of selenium weigh</u>. To do that we use selenium's<em> molar mass </em>and multiply it by the given number of moles:

0.550 mol * 78.96 g/mol = 43.43 g

The chemist would require to use 43.43 grams.

4 0

3 years ago

How am I ment to label this diagram

lora16 [44]

I believe you have to label out the positive metal ion and the delocalized electrons. They're the 2 things that makes up a metal structure.

In the diagram, the circles with the + symbol are the positive metal ions, since + represents positive. And the remaining - circles are the delocalized electrons, as electrons are negative.

And for how a metal conducts electricity, since they're delocalized mobile electrons present in any metal structures, they're able to move away from the metal to the positive side of the battery and more electrons can replace their place flowing from the negative side.

5 0

3 years ago

1) A potassium carbonate hydrate has a formula K2CO3.XH2O. 10g of the hydrate leave 7.83g of anhydrous salt upon heating. Deduce

OLEGan [10]

The formula of the hydrated potassium carbonate salt is K₂CO₃.2H₂O

Based on the calculated mass ratio of carbon and oxygen in carbon dioxide, carbon has a fixed composition.

<h3>What are hydrated compounds?</h3>

Hydrated compounds are compounds that contain one or more molecules of water physically combined with a molecule of the compound.

The formula of the hydrated potassium carbonate salt is determined as follows:

Mass of the hydrated sample = 10.0 g

Mass of anhydrous salt = 7.83

mass of water = 10 - 7.83

mass of water = 2.17 g

Molar mass of water = 18.0 g

Molar mass of anhydrous potassium carbonate = 138 g

moles of anhydrous potassium carbonate in sample = 7.83/138

moles of anhydrous potassium carbonate = 0.056 moles

moles of water in the hydrated salt = 2.17/18

moles of water in the hydrated salt = 0.12

Mole ratio of water to anhydrous salt = 0.12/0.056

Mole ratio of water to anhydrous salt = 1 : 2

Formula of hydrated salt = K₂CO₃.2H₂O

The mass ratio of carbon to oxygen in the compounds is given below:

Sample 1:

Mass ratio = 3.62 / (13.26 - 3.62)

Mass ratio = 0.38 : 1

Sample 2:

Mass ratio = 5.91 / (21.66 - 5.91)

Mass ratio = 0.38 : 1

Sample 3:

Mass ratio = 7.07 / (25.91 - 7.07)

Mass ratio = 0.38 : 1

Carbon has a fixed composition.

Learn more about hydrated compounds at: brainly.com/question/11112492

#SPJ1

6 0

1 year ago

Phosgene (COCl2) is a toxic substance that forms readily from carbon monoxide and chlorine at elevated temperatures: CO(g) + Cl2

lapo4ka [179]

Answer: Concentration of $CO$ = 0.328 M

Concentration of $Cl_2$ = 0.328 M

Concentration of $COCl_2$ = 0.532 M

Explanation:

Moles of $CO$ and $Cl_2$ = 0.430 mole

Volume of solution = 0.500 L

Initial concentration of $CO$ and $Cl_2$ = $\frac{moles}{volume}=\frac{0.430}{0.500}=0.860M$

The given balanced equilibrium reaction is,

$CO(g)+Cl_2(g)\rightleftharpoons COCl_2(g)$

Initial conc. 0.860M 0.860M 0

At eqm. conc. (0.860-x) M (0.860-x) M (x) M

The expression for equilibrium constant for this reaction will be,

$K_c=\frac{[COCl_2]}{[CO][Cl_2]}$

Now put all the given values in this expression, we get :

$4.95=\frac{x}{(0.860-x)^2}$

By solving the term 'x', we get :

x = 0.532 M

Thus, the concentrations of $CO,Cl_2\text{ and }COCl_2$ at equilibrium are :

Concentration of $CO$ = (0.860-x) M =(0.860-0.532) M = 0.328 M

Concentration of $Cl_2$ = (0.860-x) M = (0.860-0.532) M = 0.328 M

Concentration of $COCl_2$ = x M = 0.532 M

3 0

3 years ago

A porpoise sends out an ultrasonic burst and hears the echo off his favorite food in 0.13 seconds. How far away is the food sour

aalyn [17]

Answer:

The porpoise would hear its echo first because sound travels faster in water than in air. The bat would hear its echo first because the amplitude of sound waves ...

Explanation:

5 0

3 years ago