Short Answer Questions 18 points

1) What year was Mendeleev born? _______________________________________
2) Where was Mendeleev born? ______________________________________
3) Explain how Mendeleev arranged his periodic table.______________________________________
4) What were the 3 Elements that were missing from Mendeleev’s Periodic Table?
__________________________________________________________________
5) When did Mendeleev die? Exact date ____________________________________
6)Which particles are in the nucleus of an atom? ______________________________

Answers

Answer 1

1) He was born on February 8, 1834

2) He was born in Tobolsk, Russia

3) Mendeleev arranged the elements in order of increasing relative atomic mass.

4) Gallium, germanium, and scandium

5) He died on February 2, 1907

6) Protons (positive charge) and neutrons (neutral charge)


Related Questions

Order the relative rate of diffusion of the following gases from slowest to fastest

Answers

Answer:

Kr, Ar, Ne, N

Explanation:

Hope this helps

How many grams of Ag2CO3 will precipitate when excess Na2CO3 solution is added to 40.0 mL of 0.679 M AgNO3 solution

Answers

Answer:

The answer is "[tex]37.45364 \ g[/tex]"

Explanation:

Equation:

[tex]2AgNO_3 (aq) + Na_2CO_3 (aq) \longrightarrow Ag_2CO_3 (s) + 2NaNO_3 (aq)[/tex]

Calculating  the mol of  [tex]AgNO_3[/tex]:

[tex]\to V = 40.0 mL\\\\[/tex]

       [tex]= 40.0 \times 10^{-2} \ L \\\\[/tex]

[tex]\to n = Molarity \times Volume \\\\[/tex]

       [tex]= 0.679 \times 40.0 \times 10^{-2}\\\\= 27.16 \times 10^{-2} \ mol[/tex]

mol of [tex]Ag_2CO_3= \frac{1}{2} \times n\\\\[/tex]

                         [tex]= \frac{1}{2} \times 27.16 \times 10^{-2}\\\\= 13.58 \times 10^{-2}\\\\[/tex]

Calculating the molar mass of [tex]Ag_2CO_3[/tex],:

[tex]= 2\times MM(Ag) + 1 \times MM(C) + 3 \times MM(O)\\\\= 2 \times 107.9 + 1 \times 12.01 + 3 \times 16.0\\\\= 275.81 \ \frac{g}{mol}[/tex]

Calculating the mass of [tex]Ag_2CO_3[/tex],

[tex]m = mol \times molar \ mass[/tex]

   [tex]= 13.38 \times 10^{-2}\ mol \times 2.758 \times 10^2 \ \frac{g}{mol}\\\\= 37.45364 \ g[/tex]

Question 2 of 25
Rain exists in which phase?
O A Liquid
O B. Solid
C. Plasma
D. Gas

Answers

Answer:

liquid

Explanation:

correct answer hope it helps

List 5 foods that contain bacteria?

Answers

yogurt, kefir, kombucha, sauerkraut, pickles, miso, tempeh, kimchi, sourdough bread and some cheeses.

PLEASE HELP!! Circuit A consist of two wires and a battery. Circuit B consist of the same strength battery and the same type of wires, but it also contains a light bulb. Which circuit has more resistance?

Answers

Answer:

light bulb B

Explanation:

more resistance

formal charge of hcooh​

Answers

Answer:

What is the question?

PLEAE HELP ASAP WILL MARK BRAINLYLIST! Question 2 the answers are under 2

Answers

Answer:

Alkali Metals

Explanation:

They're the most reactive elements in group one.

What happens in a chemical reaction?
a. Atoms are destroyed.
b. Atoms are created.
c. Molecules are created.
d. Atoms are rearranged.
Please select the best answer from the choices provided
A
B
С
D
Pls help please :((

Answers

Answer:

During the reaction, chemical bonds break in the reactants and new chemical bonds form in the products.

Answer:

d. Atoms are rearranged.

Explanation:

Which of the following macromolecule is the main energy source for most living organisms?
A. Nucleic Acids
B. Carbohydrates
C. Lipids
D. Proteins

Answers

Answer:

Carbohydrates

Explanation:

Living things use carbohydrates as their main source of energy. The breakdown of sugars, such as glucose, supplies immediate energy for cell activities. Plants, some animals, and other organisms also use carbohydrates for structural purposes.

I think it is carbohydrates :)

An excess of oxygen reacts with 451.4 g of lead, forming 374.7 g of lead(II) oxide. Calculate the percent yield of the reaction.

Answers

Answer: The percent yield of the reaction is 77.0 %

Explanation:

[tex]2Pb+O_2\rightarrow 2PbO[/tex]

[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]

[tex]\text{Number of moles of lead}=\frac{451.4g}{207.2g/mol}=2.18moles[/tex]

[tex]\text{Number of moles of lead oxide}=\frac{374.7g}{223.2g/mol}=1.68moles[/tex]

According to stoichiometry:

2 moles of [tex]Pb[/tex] produces = 2 moles of [tex]PbO_2[/tex]

2.18 moles of [tex]Pb[/tex] is produced by=[tex]\frac{2}{2}\times 2.18=2.18moles[/tex] of [tex]PbO_2[/tex]

Mass of [tex]PbO_2[/tex] =[tex]moles\times {\text {Molar mass}}=2.18\times 223.2g/mol=486.6[/tex]

percent yield =[tex]\frac{374.7g}{486.6g}\times 100=77.0\%[/tex]

Oil is removed from the refrigerator vapor by a:

Answers

A compressor, condenser, and a evaporator

What is one example of chemical weathering affecting a rock

Answers

Hydration is a type of chemical weathering where water reacts chemically with rock H20

Answer:

one example of chemical weathering is when carbon dioxide mixes with water.

Explanation:

when dioxide mixes with water it creates carbonation.

Trinitrotoluene (TNT, C7H5N3O6) undergoes complete combustion according to the following balanced chemical equation:
C7H5N3O6(s)+214O2(g)→7CO2(g)+32N2(g)+52H2O(l)

If 25.7 g of TNT is combusted in a 0.500 L container filled with O2 at a pressure of 7.02 bar and a temperature of 298 K, calculate the maximum mass of CO2 that could be produced.

Answers

Answer:

[tex]m_{CO2}=8.33gCO2[/tex]

Explanation:

Hello.

In this case, since the chemical reaction is:

[tex]C_7H_5N_3O_6(s)+\frac{21}{4} O2(g)\rightarrow 7CO_2(g)+\frac{3}{2} N_2(g)+\frac{5}{2} H_2O(l)[/tex]

Thus, since we have the initial moles of TNT:

[tex]n_{TNT}=25.7g*\frac{1mol}{227.13g} =0.113mol[/tex]

And the initial moles of oxygen given the ideal gas equation:

[tex]n_{O_2}=\frac{6.93atm*0.5L}{0.082\frac{atm*L}{mol*K}*298K}=0.142molO_2[/tex]

Given the 1:7 mole ratio between TNT and carbon dioxide and the 21/4:7 mole ratio between oxygen and carbon dioxide, we compute the yielded moles by each reactant:

[tex]n_{CO_2}^{by\ TNT}=0.113molTNT*\frac{7molCO_2}{1molTNT}=0.791molCO_2\\\\ n_{CO_2}^{by\ O_2}=0.142molO_2*\frac{7molCO_2}{21/4molO_2}=0.189molCO_2[/tex]

Thus, since oxygen yields less moles of carbon dioxide than TNT, we infer it is the limiting reactant, therefore, the produced mass of carbon dioxide is:

[tex]m_{CO2}=0.189molCO2*\frac{44.01gCO2}{1molCO2}\\\\m_{CO2}=8.33gCO2[/tex]

Best regards!


The three lines in this Lewis dot structure represent the.
A)
three valence electrons of dinitrous oxide.
B)
six electrons in the triple bond of diatomic nitrogen.
C)
three electrons joining two nitrogen atoms in a diatomic molecule.
D)
three double bonds between the valence electrons of diatomic nitrogen.

Answers

Answer:

B) . six electrons in the triple bond of diatomic nitrogen

Explanation:

The three line in this Lewis dot structure represents the six electrons in the triple bond of diatomic nitrogen.

Nitrogen is made up of 7 electrons with 5 valence ones.

 A lewis structure is made up of the symbol of the element surrounded by dot to represent the valence electrons.

  In this nitrogen molecule, both species share  6 electrons. This makes each nitrogen atom isoelectronic with neon.

Pls pls pls pls pls pls help

Answers

Non living ,bacteria, parasites, fungi and viruses. Viruses are infectious agents. Vaccines. Bacteria are usually singled celled strep throat. Outside, anti fungal, host organism, weaker

What volume. In liters, of H2O(g) measured at STP is produced by the combustion of 15.63 g of natural gas (CH4) according to the following equation? CHale) +20269) CO2 + 2H2008)

Answers

Answer:

V = 43.95 L

Explanation:

Given data:

Mass of CH₄ decomposed = 15.63 g

Volume of H₂O produced at STP = ?

Solution:

Chemical equation:

CH₄ + 2O₂    →       2H₂O  + CO₂

Number of moles of CH₄:

Number of moles = mass/molar mass

Number of moles = 15.63 g/ 16 g/mol

Number of moles = 0.98 mol

Now we will compare the moles of H₂O with CH₄.

                         CH₄              :              H₂O

                           1                 :                2

                        0.98             :            2×0.98 = 1.96 mol

Volume of hydrogen:

PV = nRT

1 atm × V = 1.96 mol × 0.0821 atm.L/mol.K × 273.15 K

V = 43.95atm.L / 1atm

V = 43.95 L

How does the VSEPR theory explain molecular shape?
A. Valence electrons modify core electron orbitals.
B. Intermolecular forces distort electron bonds.
C. Electron pair attractions pull atoms together.
D. Electron pairs repelling each other push atoms apart.

Answers

Answer:

D. Electron pairs repelling each other push atoms apart

Explanation:

Hope this helps :) I just got it wrong on ap3x so I'm sure this is right

The VSEPR theory explain molecular shape by stating that the Electron pairs repelling each other push atoms apart. Hence, Option (D) is correct

What is VSEPR theory ?

Valence shell electron pair repulsion (VSEPR) theory, is a model used in chemistry to predict the geometry of individual molecules from the number of electron pairs surrounding their central atoms.

It is also named the Gillespie-Nyholm theory after its two main developers, Ronald Gillespie and Ronald Nyholm.

Therefore, The VSEPR theory explain molecular shape by stating that the Electron pairs repelling each other push atoms apart. Hence, Option (D) is correct.

Learn more about VSEPR theory here ;

https://brainly.com/question/2293021

#SPJ2

Draw and name the structures of the carboxylic acids and esters you put together using molecular models.

Answers

Answer:

This question is incomplete

Explanation:

However, when the carboxylic acids and esters put together are obtained, the procedure below can be followed in drawing and naming them.

For carboxylic acid,

1) it should be noted that the functional group here is -COOH which is drawn as -C = OH

      |

     OH

2) The carbon of the functional group is included among the carbon to be counted when naming the structure. For example, the compound below is propanoic acid.

CH₃CH₂COOH - As you can see that there are 3 carbons linked chain there.

3) As can be seen in (2) above, the suffix "oic" is used to name carboxylic acids

4) The carbon chain here is saturated (meaning there is no double or triple bond within the carbon chain)

Example of a structure of carboxylic acid is

H₃C - CH₂ - CH₂ - C = OH

                              |

                             OH

The structure above is a butanoic acid

For ester

1)The functional group here is -COO- . which can be drawn as

- C = O

   |

  O -

(meaning one oxygen atom is double bonded to the carbon and the other oxygen atom is bonded to another carbon chain)

2) The alkyl group attached to the oxygen atom is first of all mentioned before the carbon chain attached from the left is mentioned. For example, CH₃CH₂CH₂COOCH₂CH₃ is ethyl butanoate

3) As seen from (2) above, the suffix "oate" is used to end the name of esters

4) As also seen from (2) above, the carbon of the functional group is also included while counting the carbon chain of the parent name (butanoate).

5) The carbon chains here are also saturated.

Example of this ester is

CH₃CH₂C = O

              |

             O - CH₂CH₃

The name of this compound is ethyl propanoate

Answer them please thanks

Answers

Answer:

(3) sorry if I'm wrong

7.  (1-fertilization [sorry if wrong again]

8. (4-mitosis

Explanation:

I'm learning about this right now...Sorry if I'm wrong but I'm pretty sure they're right! Hope this helps tho! if I'm right maybe mark me brainliest?

PLEASE HELP!! I WILL MARK THE 1st ONE BRAINLIEST!

Answers

Answer:

I hope you do well on the test good luck

Explanation:

What is the velocity if you travel 60 m to the right in 20 seconds

Answers

Answer:

The velocity would be if m was meters +1200

Explanation:

im smart

which stimulate causes high energy emotional elation dehydration and damage serotonin producing neurons

Answers

Answer:

ecstasy

Explanation:

A 7.28 g sample of chromium metal was heated to produce chromium oxide. The weight of the compound was 10.63 g. What is the percent chromium in this compound?

Answers

Answer:

68.48%

Explanation:

The percent mass of an element in a compound tells us about the amount of such element contributed to the total compound.

In this case, 7.28 g sample of chromium metal was heated to produce chromium oxide with weight of 10.63 g. The percent mass of chromium in chromium oxide can be calculated by using the formula:

%mass of Cr = mass of Cr/mass of Chromium oxide × 100%

%mass of Cr = 7.28/10.63 × 100

%mass of Cr = 0.6848 × 100

%mass of Cr = 68.48%

The atomic masses of 20Ne (90.48 percent), 21Ne (0.27 percent), and 22Ne (9.25 percent) are 19.9924356, 20.9938428, and 21.9913831 amu, respectively. Calculate the average atomic mass of neon. The percentages in parentheses denote the relative abundance

Answers

Answer:

20.180042 amu

Explanation:

From the question given above, the following data were obtained:

Isotope A (20Ne)

Mass of A = 19.9924356 amu

Abundance (A%) = 90.48%

Isotope B (21Ne):

Mass of B = 20.9938428 amu

Abundance (B%) = 0.27%

Isotope C (22Ne):

Mass of C = 21.9913831 amu

Abundance (C%) = 9.25%

Average atomic mass of Neon =.?

The average atomic mass of Neon can be obtained as follow:

Average atomic mass = [(mass of A × A%)/100] + [(mass of B × B%)/100] + [(mass of C × C%)/100]

= [(19.9924356 × 90.48)/100] + [(20.9938428 × 0.27) /100] + [(21.9913831 × 9.25) /100]

= 18.0891557 + 0.05668338 + 2.03420294

= 20.180042 amu

Therefore, the average atomic mass of Neon is 20.180042 amu

What is the best-known feature of sedimentary
rocks?
A. ripple marks
B. fossils
C. graded bedding
D. cross-bedding

Answers

Answer:

option is (b)

Explanation:

please mark me as brilliant

The answers is b because it layers on so it is b

What type of bond would be expected between Mg and Ti?
A.hydrogen bond
Bionic bond
C.covalent bond
D.metallic bond

Answers

C. covalent bond.... hope this helps!

At which temperature can water contain the most
dissolved sugar?

Answers

Answer:

At 10ºC or 50ºF water can cotain the most dissolved sugar.

What is the specific rotation of a sample of carvone that is an equal mixture of the R and S enantiomers

Answers

Answer:

Zero

Explanation:

An an equal mixture of the R and S enantiomers of carvone is called a racemic mixture.

In a racemic mixture, the R enantiomer rotates plane polarized light in one direction while the S enantiomer rotates plane polarized light in another direction.

This cancels out the rotation due to each enantiomer since they are equal in magnitude but opposite in direction leading to a specific rotation of zero for the racemic mixture.

A. filtration B. sieving C. using a magnet D. decantation
E. evaporation
Directions: Choose the best technique that can be used to separate the substances or
materials in each mixture. Write the letter of your answer on the space before the nu
1. Cornstarch and water
2. Iron and sulfur
3. Rice grains and stones
4. Pebbles and soil
5. Muddy water
6. Ground pepper and water
7. Flour and coarsely ground corn
8. Needles in a box of beads
9. Sesame seeds in soy sauce
10. Pebbles and iron nails
11. Fine sand from rocks
12. Sand from water
13. Gravel and sand
14. Salt and iron filings
15. Pins from assorted buttons
16. Coconut oil from coconut milk
17. Sand and pebbles
18. Pasta from water
19. Sand and thumb tacks
20. Salt solution​

Answers

Answer:

Explanation:

1. Cornstarch and water - decantation

2. Iron and sulfur

3. Rice grains and stones - sieving

4. Pebbles and soil - decantation

5. Muddy water - decantation

6. Ground pepper and water - decantation

7. Flour and coarsely ground corn - sieving

8. Needles in a box of beads - using a magnet

9. Sesame seeds in soy sauce -

10. Pebbles and iron nails - using a magnet

11. Fine sand from rocks - sieving

12. Sand from water - filtration

13. Gravel and sand - sieving

14. Salt and iron filings - sieving

15. Pins from assorted buttons - using a magnet

16. Coconut oil from coconut milk - filtration

17. Sand and pebbles - sieving

18. Pasta from water - sieving

19. Sand and thumb tacks - using a magnet

20. Salt solution - filtration

A scientist is considering formaldehyde (HCHO) for use in an experiment. She is studying the strength of triple bonds in molecules. Is
ormaldehyde a good choice for her to use? Why?
A. Yes, HCHO has three triple bonds.
B. Yes, HCHO has one triple bond.
C. No, HCHO has a double bond but no triple bonds.
D. No, HCHO has only single bonds.

Answers

Answer: C) No, HCHO has a double bond but no triple bonds
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