All categories

2 years ago

Please help asap!! How many groups did Mendeleev's original Periodic Table of Elements have?

1 answer:

8 0

The columns, called groups, contain elements with similar chemical behaviours. Six groups have accepted names as well as assigned numbers: for example, group 17 elements are the halogens; and group 18 are the noble gases.

Hope this helps :)

You might be interested in

Calculate the total number of days therapy available within a 300 ml bottle of ranitidine (as hydrochloride) 75 mg/5 ml. oral so

Lisa [10]

<u>Answer:</u> This therapy is available for 15 days.

<u>Explanation:</u>

We are given:

Oral solution dosage = 75 mg/5 mL

To calculate the volume of oral situation for single dose per, we use unitary method:

The volume required for 75 mg of solution is 5 mL

So, the volume required for 300 mg of solution will be = $\frac{5mL}{75mg}\times 300mg=20mL$

The total volume of the ranitidine bottle = 300 mL

To calculate the number of days, we divide the total volume of the bottle by the volume of dose taken per night, we get:

$\text{Number of days}=\frac{\text{Total volume}}{\text{Volume of dose taken per night}}=\frac{300mL}{20mL}=15$

Hence, this therapy is available for 15 days.

8 0

3 years ago

The job of the human heart is to circulate blood through all of the body's arteries, capillaries, and veins. The job of the huma

weeeeeb [17]

B
All cells new oxygen and blood is a way for them to get it

3 0

3 years ago

Read 2 more answers

What can be a personal question about atoms

Damm [24]

Heres a list of questions

1. Define atom.

Atom is the smallest particle of a substance.

2. What are the subatomic particles found in an atom?

The subatomic particles found in an atom are electrons, protons, and neutrons.

3. Define charged particle.

Charged particle is a particle that has an electric charge.

4. Define electric charge.

Electric charge is the physical property of particles such as electrons and protons. Electric charge causes other particles to experience a force.

5. What are the charged particles found in an atom?

Electrons and protons are the charged particles found in an atom.

6. What are the different types of charged particles?

Charged particles are of two types: positive charges and negative charges.

7. What are the negatively charged particles in an atom?

Electrons are the negatively charged particles in an atom.

8. What are the positively charged particles in an atom?

Protons are the positively charged particles in an atom.

9. What is the mass of an electron?

The mass of an electron is 9.107 × 10-31 kilograms.

10. What is the mass of a proton?

The mass of a proton is 1.672 × 10-27kilograms.

11. Define atomic number.

The total number of protons in the nucleus of an atom is called atomic number.

12. Define neutron number.

The total number of neutrons in the nucleus of an atom is called neutron number.

13. Define mass number.

Mass number is the total number of protons and neutrons in the nucleus of an atom.

Mass number can be mathematically written as

Explanation:

5 0

2 years ago

Read 2 more answers

Hydrogen gas (a potential future fuel) can be formed by the reaction of methane with water according to the following equation:

rusak2 [61]

Answer:

60.42% is the percent yield of the reaction.

Explanation:

Moles of methane gas at 734 Torr and a temperature of 25 °C.

Volume of methane gas = V = 26.0 L

Pressure of the methane gas = P = 734 Torr = 0.9542 atm

Temperature of the methane gas = T = 25 °C = 298.15 K

Moles of methane gas = n

$PV=nRT$

$n=\frac{PV}{RT}=\frac{0.9542 atm\times 26.0L}{0.0821 atm L/mol K\times 298.15 K}=1.0135 mol$

Moles of water vapors at 700 Torr and a temperature of 125 °C.

Volume of water vapor = V' = 23.0 L

Pressure of water vapor = P' = 700 Torr = 0.9100 atm

Temperature of water vapor = T' = 125 °C = 398.15 K

Moles of water vapor gas = n'

$P'V'=n'RT'$

$n'=\frac{PV}{RT}=\frac{0.9100 atm\times 23.0L}{0.0821 atm L/mol K\times 398.15 K}=0.6402 mol$

$CH_4(g)+H_2O(g)\rightarrow CO(g)+3H_2(g)$

According to reaction , 1 mol of methane reacts with 1 mol of water vapor. As we can see that moles of water vapors are in lessor amount which means it is a limiting reagent and formation of hydrogen gas will depend upon moles of water vapors.

According to reaction 1 mol of water vapor gives 3 moles of hydrogen gas.

Then 0.6402 moles of water vapor will give:

$\frac{3}{1}\times 0.6402 mol=1.9208 mol$ of hydrogen gas