Who made the first periodic table of the elements?
O A. Ernest Rutherford
O B. Dmitri Mendeleev
O C. Niels Bohr
O D. Henry Moseley

Answers

Answer 1

The periodic table was invented by Russian chemist Dmitri Mendeleev in 1869.

Answer 2

Answer:

B. Dmitri Mendeleev

Explanation:


Related Questions

Newton’s Second Law of Motion: The Law of 1. __________(Inertia/Acceleration)

The acceleration of an object is 2. _____________ (directly/inversely)

proportional to the magnitude of the net force acting on it, in the

3. _____________ (same/opposite) direction as the net force, and

4. _____________ (directly/inversely) proportional to the

5. _____________ (mass/weight) of the object.​

Answers

Answer:

acceleration

inversly

opposite

directly

mass

Which of the following describes the motion of water molecules in ice?
A. They do not move at all.
B. They are vibrating slightly.
C. They move the same as in a liquid.
D. They move faster than in a liquid.

Answers

B. They are vibrating slightly

Explanation:

This is because the particles are really close together and they vibrate on the spot.

Hope this is useful

Mark Brainliest please

Answer : the answer is B


The answer is option B "they are vibrating slightly." In ice the molecules are stuck together and shaking like a bunch of little people together trying to keep warm. ...


help in this please....................​

Answers

c) because rays contain electrons

Which is the most likely way an automotive engineer would use chemistry?

A. By testing the maximum speed and stopping distance of a new
car

B. By doing market research to determine which types of cars
consumers want

C. By designing cars that are more aerodynamic

D. By making parts that reduce the pollutants cars emit

Answers

Answer:

by making parts... emit

(02.01 MC) Which state of matter does this model represent?
O Solid
O Liquid
O Gas
O Plasma​

Answers

Answer:

Hello There!!

Explanation:

I believe the answer is O Gas.

hope this helps,have a great day!!

~Pinky~

What makes plants the beginning of the food chain?


please answer my question aswell as my last one!

Answers

plants are at the beginning of the food chain because they can’t protect them self from bugs and animals eating them. plus plans eat there own kind of food in the ground.

Answer: A

Explanation:

i just took the quiz and it was right!

30. Which two notations represent atoms that are isotopes of the same
element?
A) 31 Sn and 30°Sn
B) 581 Sn and 13 Sn
C) 3°O and LOF
D) 19 Cl and 18K

Answers

Answer: 581 Sn and 13 Sn

Explanation:

581 Sn and 13 Sn are both Sn which are the same element with different masses. Isotopes are same element with different masses and the elements can have different masses because of different number of neurons

Which piece of information do you need to determine whether a hydrocarbon
is saturated or unsaturated?
A. The type of C-C bonds in the molecule
B. The number of C-C bonds in the molecule
C. The type of C-H bonds in the molecule
D. The number of C-H bonds in the molecule

Answers

Answer:

A

Explanation:

Saturated means all the carbon atoms has four single bonds around it. These bonds are strong and won't break easily therefore saturated hydrocarbons aren't very reactive

Unsaturated means in one instance the C has a double bond with another carbon. This double bond can be easily broken therefore making unsaturated compounds more reactive than saturated compounds

So saturation deals with the type of bonds the carbon has with other carbon atoms. (The C-C bonds)

The ideal gas law equation is: PV = nRT
Use the ideal gas law to calculate the moles of gas in a container that has a pressure
of 700kpa, volume of 2L and a temperature of 450K.

Answers

Answer:

The answer is the first option 0.37 moles

Explanation:

the ideal gas law is PV = nRT, so in the terms of n,

n = PV/RT (divide both sides by RT to let n stand alone)

given: P = 700 kpa, V = 2L, T = 450 K , R = 8.31

n = (700 * 2) / (8.31 * 450)

= 1400/3739.5

= 0.34

What is used to describe the conditions of a reaction at equilibrium?
O A. A reaction-rate constant
O B. An activation energy
O C. An ideal gas constant
O D. An equilibrium constant
SUBM

Answers

i think the awnser is D

ch
Heat depends on which factor?
how fast the molecules are vibrating
O how big the molecules are
how close the molecules are together
O none of the above

Answers

Answer:

Hello There!!

Explanation:

I believe the answer is how fast the molecules are vibrating.

hope this helps,have a great day!!

~Pinky~

Something that can be broken down by living organisms is
a.
biodegradable.
c.
ecological.
b.
economic.
d.
renewable.


Please select the best answer from the choices provided

A
B
C
D

Answers

The answer is A: biodegradable.

Answer:

hii

needed points

One way industrial chemists aim to improve manufacturing and sales is by manipulating extemal factors to increase the rate of the reaction.
As an industrial chemist you have been asked by the CEO of your company to propose conditions that will increase the rate of production of
acetaminophen (the active ingredient in Tylenols). In a well-written letter to the CEO include three possible methods for increasing the
reaction rate and explain why each proposed change will increase the reaction rate Justity your recommendations using scientinc principles
The chemical synthesis of acetaminophen C.H.NO, is represented by the following equation

Answers

There are several methods that can be employed to increase yield in the chemical synthesis of acetaminophen.

What is chemical synthesis?

The term chemical synthesis has to do with the method of producing a chemical substance from other chemical substances.

It is usual in industrial chemistry to seek to optimize the yield of the target product. In the chemical synthesis of acetaminophen as shown in the image attached, the yield of the product can be increased by;

1) Removal of the ethanoic acid byproduct to drive the forward reaction

2) Increasing the concentration of each of the reactants to ensure that more product is obtained.

3) Operating the process at a higher temperature to ensure that reaction is more efficient.

Learn more about rate of reaction:https://brainly.com/question/13440548

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4 NH3 + 7 O2 → 4 NO2 + 6 H2O What is the mole ratio between oxygen and nitrogen dioxide? 7 moles to 6 moles 4 moles to 6 moles 7 moles to 4 moles 4 moles to 4 moles

Answers

Answer:

7:4

Explanation:

O2 : NO2

7 : 4

hope this helps :)

can someone answer this please

Answers

It is copper because it is the most maleable

Which of the following would increase the pressure of a gas?

Answers

Answer:

What are the answer choices????

Answer:

An increase in the number of gas molecules in the same volume container increases pressure. A decrease in container volume increases gas pressure. An increase in temperature of a gas in a rigid container increases the pressure.

Explanation:

Increasing the temperature would increase the pressure on the system

I need to know the coefficient order

Answers

Explanation:

in mathematics use Pascal triangle

20. Show a correct numerical setup for calculating the molarity of the KOH * (aq) solution. Then state the calculated value of the molarity .

Answers

Answer:

[tex]M_b = \frac{0.10M * 9.50mL}{3.80mL}[/tex] ---- The setup

[tex]M_b = 0.25M[/tex] --- The molarity of KOH

Explanation:

Given

I will answer the question with the attached titration data

Required

The set and the value of the molarity of KOH

First, calculate the volume of acid (HCL) used:

[tex]V_a = Final\ Reading - Initial\ Reading[/tex]

[tex]V_a = 25.00mL - 15.50mL[/tex]

[tex]V_a = 9.50mL[/tex]

Calculate the final volume of base (KOH) used:

[tex]V_b = Final\ Reading - Initial\ Reading[/tex]

[tex]V_b = 8.80mL - 5.00mL[/tex]

[tex]V_b = 3.80mL[/tex]

The numerical setup is calculated using::

[tex]M_a * V_a = M_b * V_b[/tex]

Where

[tex]V_a = 9.50mL[/tex]

[tex]V_b = 3.80mL[/tex]

[tex]M_a = 0.10M[/tex] --- the given molarity of HCL

So, we have:

[tex]M_a * V_a = M_b * V_b[/tex]

[tex]0.10M * 9.50mL = M_b * 3.80mL[/tex]

Make Mb the subject

[tex]M_b = \frac{0.10M * 9.50mL}{3.80mL}[/tex] ---- The correct numerical setup

The solution is then calculated as:

[tex]M_b = \frac{0.10M * 9.50mL}{3.80mL}[/tex]

[tex]M_b = \frac{0.10 * 9.50}{3.80}M[/tex]

[tex]M_b = \frac{0.95}{3.80}M[/tex]

[tex]M_b = 0.25M[/tex]

Atoms of which pair of elements will form ionic bonds in a compound?

Answers

One atom of sodium and one atom of fluorine
I think the answer is A

What the larger number in the block of an element in the periodic table​

Answers

Answer:

f-block

Explanation:

How many grams of Lioh are in 1.7 moles?

Answers

Answer:

40.7g

Explanation:

so mass = moles × mr( 6.94+16+1)

=1.7 × 23.94

= 40.698

so 3 S.F = 40.7 g

hope this helps :)

What is the percent composition by mass of nitrogen in the compound NH3 (gram-formula mass - 17 g/mol)?
A.18%
B.25%
С.75%
D.82%

Answers

Answer: d 82%. Your welcome

Witch part of an atom is mostly empty space?

Answers

Outside of the nucleus, an atom is mostly empty space, with orbiting negative particles called electrons whizzing through it.

Hydrogen and nitrogen react to form ammonia. The chemical equation for this reaction is shown here. 3 H2(g) + N2(g) 2 NH3(g). What amount of hydrogen will produce 44.0 mol of ammonia?
66.0 mol
88.0 mol
132.0 mol
29.3 mol

Answers

Answer:

someone already answered but i think it's 132.0 mol too

Compound A reacts with alcoholic KOH to yield compound B which on ozonolyzises followed by the reaction with Zn/H2O gives methanal and propanal Compound A is

Answers

Answer:

1-chlorobutane

Explanation:

Given that :

-- The compound A is made to react with alcoholic KOH and produce compound B.

-- The compound B on Ozonolysis produces methanol as well as propanol

The compound A should be a haloalkanes as treatment of haloalkanes with the alcoholic KOH, it will give alkene.

[tex]$CH_3CH_2CH_2CH_2Cl+KOH( \text{alcohol}) \rightarrow CH_3CH_2CH=CH_2+KCl+H_2O$[/tex]

So, the compound B should be Butene

Now the ozonolysis of the compound B or butene will give methanol and propanal as shown :

[tex]$CH_3CH_2CH=CH_2 \rightarrow CH_2O+CH_3CH_2CHO$[/tex]

Therefore, the compound A is 1-chlorobutane.

Adding a catalyst to a system at equilibrium lowers the activation energy required by a system, which system, which shifts the equilibrium position toward the products.

True or false?

Answers

Answer: False

Explanation: Took the test

Answer:

False

Explanation:

Question 14 of 30
Which of the following elements has 1 valence electron?
The Periodic Table
A. Sodium (Na)
B. Chlorine (CI)
C. Calcium (Ca)
D. Helium (He)
SUBMIT

Answers

Answer:

A. Sodium (Na)

Explanation:

The total number of electrons in the outermost principal energy level of an element is called the valence electrons of that element.

Na (11)---→1s2 2s2 2p6 3s1

There 1 electron in the outermost principal energy level of Sodium. So, the number of valence electron of Sodium is 11.

Answer:

Na

Explanation:

I was learning about it recently, that dude's right, it's Sodium

How many moles are equivalent to 365 g of aluminum chloride? Using the dimensions analysis. Show work

Answers

Answer:

≈ 2.74 mol [tex]AlCl_{3}[/tex]

(I rounded to 3 sig figs because the starting amount has 3 sig figs.)

Explanation:

[tex]\frac{365g AlCl_{3}}{1}*\frac{1 mol AlCl_{3}}{133.34g AlCl_{3}} =[/tex] 2.73736313184 mol [tex]AlCl_{3}[/tex] ≈ 2.74 mol [tex]AlCl_{3}[/tex]

Hope this helps!

The aximuthal quantum number of an orbital is 3. What are the possible values of m?​

Answers

For a given valye of l(l shell), values of m are from -l to 0 to l, so m could be; -3, -2, -1, 0, +1, +2, +3.

Easyy!

the value of m is equal to 2l+1 so there must beseven values for m.

m can have values from -l through zero to +l so the values are -3, -2, -1, 0, +1, +2 and +3.

What type of molecule is shown below?

A. Ether
B. Alcohol
C. Aldehyde
D. Ketone

Answers

The answer is choice C. Adlehyde

The given molecule is an aldehyde with the formula HCHO. It is the simplest and primary aldehyde . Hence, option c is correct.

What are aldehydes ?

Aldehydes are a class of organic compounds that contain a carbonyl group (a carbon double-bonded to an oxygen) at the end of a carbon chain. The general formula for an aldehyde is RCHO, where R is a substituent or side chain attached to the carbonyl group.

Aldehydes are often characterized by their distinctive odor, which can be described as pungent and irritating. Some common aldehydes include formaldehyde (used in building materials and as a disinfectant), acetaldehyde (found in alcoholic beverages), and benzaldehyde (used in food flavorings).

Aldehydes are important intermediates in many chemical reactions, and they are used in a variety of industrial and laboratory applications. They can be synthesized by the oxidation of primary alcohols or by the partial oxidation of hydrocarbons. The given compound is formaldehyde HCHO.

Find more on aldehydes:

https://brainly.com/question/30902678

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