According to the periodic table, which two elements have an atomic mass less than twice their atomic number?

Answers

Answer 1

Answer:

Hydrogen and oxygen

Explanation:

Hydrogen

2 × atomic number = 2

atomic mass = 1.008 amu

Oxygen

2 × atomic number = 16

atomic mass = 15.999 amu


Related Questions

When two liquids are mixed, they begin to fizz, this is an example of a __1__ change. You know this because __2__.

Answers

Answer:

1.chemical change 2, when two chemicals are mixed they have mix two chemcials into one liquid

Explanation:

which of the following is not true for chemical change

Answers

Answer:

"They can be reversed by physical changes."

Explanation:

A chemical change can form a new substance, can be detected by the change in color and they have properties different from their starting materials.

4. The cup is a volume widely used by cooks in the UAE. One cup is equivalent to 237 mL.
a. If 1 cup of olive oil has a mass of 216 g, what is the density of olive oil in kg/mL?


b. Convert the density from part A to kg/mL. Write your answer in scientific notation.

Answers

Taking into account the definition of density and scientific notation, the density of olive oil is 0.000911 [tex]\frac{kg}{mL}[/tex] or 9.11×10⁻⁴[tex]\frac{kg}{mL}[/tex]

Density is defined as the property that matter, whether solid, liquid or gas, has to compress into a given space.

In other words, density is a quantity that allows us to measure the amount of mass in a certain volume of a substance.  That is, density is the relationship between the weight (mass) of a substance and the volume it occupies.

The expression for the calculation of density is the quotient between the mass of a body and the volume it occupies:

[tex]density=\frac{mass}{volume}[/tex]

In this case, you know that:

mass= 216 g= 0.216 kg (being 1000 g= 1 kg)volume= 237 mL

Replacing in the definition of density:

[tex]density=\frac{0.216 kg}{237 mL}[/tex]

Solving:

density= 0.000911 [tex]\frac{kg}{mL}[/tex]

On the other side, scientific notation is a quick way to represent a number using powers of base 10.  

The numbers are written as a product:

a×10ⁿ

where:

a is a real number greater than or equal to 1 and less than 10, to which a decimal point is added after the first digit if it is a non-integer number. n = a whole number, which is called an exponent or an order of magnitude. Represents the number of times the point decimal is shifted. It is always an integer, positive if it is shifted to the left, negative if it is shifted to the right.

In this case, the density expressed in scientific notation is: 9.11×10⁻⁴[tex]\frac{kg}{mL}[/tex]

In summary, the density of olive oil is 0.000911 [tex]\frac{kg}{mL}[/tex] or 9.11×10⁻⁴[tex]\frac{kg}{mL}[/tex]

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about density: brainly.com/question/952755?referrer=searchResults brainly.com/question/1462554?referrer=searchResultsscientific notation: brainly.com/question/18073768?referrer=searchResults

What is the volume of water needed to prepare 5000 ml of 0.1 M HCL from a stock solution of4 M
e) 125 ml
b) 375 ml
c) 500 ml
d) none of them

Answers

Hey There :

Volume initial = ?

Volume final = 5000 mL

Molarity initial = 4 M

Molarity final = 0.1 M

Therefore :

Mi * Vi = Mf * Vf

4 * vi = 0.1 * 5000

4 vi = 500

Vi = 500 / 4

Vi = 125 mL

Answer A

Hope this helps!

HELP PLEASEEEEEEEEEEEEEEEEEEE

Answers

Answer:

1-air

2-decrease

3-water

4-gas

5-liquid

I THINK the answer to part b is A but I am not entirely sure

Explanation:

Which of these is a common to all chemical changes

A) A new change of sate occurs

B) A change of color occurs

C) a new substance is produced

D) heat is released into the air

Answers

C. A new substance is produced. All others are physical changes.

Answer:

c

a new substance is produced

what is the resonance structure of ch3​

Answers

Answer:

For the CH3- structure use the periodic table to find the total number of valence electrons for the CH3- molecule. Once we know how many valence electrons there are in CH3- we can distribute them around the central atom with the goal of filling the outer shells of each atom.

In the Lewis structure of CH3- structure there are a total of 14 valence electrons.

Also note that you should put the CH3- Lewis structure in brackets with as 1- on the outside to show that it is an ion with a negative one charge.

----- Steps to Write Lewis Structure for compounds like CH3- -----

1. Find the total valence electrons for the CH3- molecule.

2. Put the least electronegative atom in the center. Note: Hydrogen (H) always goes outside.

3. Put two electrons between atoms to form a chemical bond.

4. Complete octets on outside atoms.

5. If central atom does not have an octet, move electrons from outer atoms to form double or triple bonds.

Lewis Structures, also called Electron Dot Structures, are important to learn because they help us understand how atoms and electrons are arranged in a molecule. This can help us determine the molecular geometry, how the molecule might react with other molecules, and some of the physical properties of the molecule (like boiling point and surface tension).

Explanation:

CH3CNO can be represented by at least three different but valid Lewis structures called resonance forms, or resonance structures, shown below.

High tides are located at__

A an B

B an D

B an C

Answers

Answer:

b and c since they bulge

Explanation:

What is the mass of 2.3 x 10²¹ atoms of bromine?​

Answers

Answer:0.305g

Explanation:

mass = 79.9x(2.3 x 10^21) / (6.02 x 10^23)

= 0.305

helppppppppppppppppppppppppppppp

Answers

Answer:

any form of water that falls from the sky

What are the substances you start with in a chemical reaction called?
A. The intermediates

B. The products

C. The mixture

D. The reactants

Answers

The answer is B the products those are the products your starting off with
I think it’s answer D. The reactants

Define physical and chemical properties, provide three examples of each, discuss their reversibility, and
explain the fundamental differences between them.

Answers

Physical properties are defined as the properties
which can be observed without changing its
chemical composition.
For example: color, volume, and molecular
weight.
Chemical properties are defined as the
properties which can be observed only after
changing chemical identity of the substance.
For example: reactivity, toxicity, and
flammability.
The fundamental differences between physical
and chemical properties are as follows:
Chemical properties are related to
chemical bonds of the substance while physical
properties are not.
In chemical properties, chemical identity of
substance changes while physical properties do
not have any change.
Chemical properties predict the reaction of
substance while physical properties only describe
the appearance of the substance.

What Group is this atom located use a number only
*

Answers

7 count the dots in the middle for you answer and if not it’s 3

Is the molecule H2+ stable?

Answers

Answer: Yes

The antibonding orbital is empty. Thus, H2 is a stable molecule.

Answer: yes it is

Explanation:Bond order

The antibonding orbital is empty. Thus, H2 is a stable molecule

A student sets up a titration apparatus with 25 mL of potassium. hydroxide in the flask. In three to five sentences, explain how the student can use a 0.1 M solution of hydrobromic acid to determine the concentration of potassium hydroxide in the reaction.

Answers

The concentration of 25 mL of potassium hydroxide can be determined from 0.1 M solution of hydrobromic acid by titration.

Titration involves the process by which the concentration of an unknown solution is determined by reaction a known volume of the unknown solution with a carefully measured volume of a standard solution. By determining the volume of the standard solution required to react completely with the solution of unknown concentration, its concentration can be accurately determined by calculation.

In order to determine the concentration of  25 mL of potassium hydroxide, this volume of solution is put into a conical flask and titrated against a known volume of 0.1 M solution of hydrobromic acid. At the end point, usually signified by a color change, the concentration of the 25 mL of potassium hydroxide solution can be calculated from the stoichiometry of the reaction.

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Please help me. I can’t give too much points bc I don’t have too much.

QUANTUM=
The relationship between energy and frequency=
E = hy
EN
h=
V=
Albert Einstein: PHOTONS

Answers

Answer is photons hope this helps

helpppppppppppppppppppppppppppp

Answers

Answer:

1)

Explanation:

ok this is a write answer

4) Water warms up and becomes vapor

Alex mixed soy sauce and vinegar and created mixture that has a uniform appearance all throughout. he also noticed that the components are not recognizable and are evenly mixed.Which type of mixture was he able to create

a.heterogeneous
b.homogeneous
c.solid in liquid
d.solid in liquid​

Answers

Answer:

b.homogeneous

Can I have a Brainliest please?

Explanation:

2.When copper (II) nitrate reacts with sodium hydroxide, copper (11) hydroxide is produced.
How many grams of copper (11) hydroxide can be prepared from 2.7 g of copper (II) nitrate
reacting with sodium hydroxide?

Answers

Answer:

 

2Cu + S ~~~> Cu2S Copper (C) reacts with sulfur (S) to form copper sulfide as shown in the equation. A scientist adds 12.7 grams of Cu to 3.2 grams of S to start the reaction.

Explanation:

When doing medical research with human subjects, which four limitations are unavoidable?

Answers

Answer:

Answer

The limitations are-

1. Privacy of the individuals involved in the research process.

2. Physical and psychological risks should be minimized

3. The subjects should be chosen equitably

4. Only reasonable exposure to risks is admissible.

Explanation

The privacy of the individuals involved in the research must be taken into consideration. This will ensure safety of patient data and information. The risk of physical and physiological well being of the person must be taken into consideration in such a research. In addition to that, the subject must be made to understand every procedure and the risks involved before testing. Moreover, only minimal exposure to risks is allowed and must have been previously tested in animals to avoid deaths.

Pure iron, Fe , can be produced from an ore called hematite, Fe2O3 , by reaction with carbon at high temperatures. 2Fe2O3+3C⟶4Fe+3CO2 How many tons of hematite must react with carbon if an iron company needs to make 49 tons of iron?

Answers

70 tons of hematite (Fe₂O₃) is needed to produce 49 tons of iron (Fe).

We'll begin by calculating the tons of hematite (Fe₂O₃) that reacted and the tons of Fe produced from the balanced equation. This is illustrated below:

2Fe₂O₃ + 3C —> 4Fe + 3CO₂

Molar mass of Fe₂O₃ = (56×2) + (16×3) = 160 g/mol

Mass of Fe₂O₃ from the balanced equation = 2 × 160 = 320 g

Divide by 907185 to express in ton

320 / 907185 = 0.000353 ton

Molar mass of Fe = 56 g/mol

Mass of Fe from the balanced equation = 56 × 4 = 224 g

Divide by 907185 to express in ton

224 / 907185 = 0.000247 ton

SUMMARY

From the balanced equation above,

0.000353 ton of Fe₂O₃ reacted to produce 0.000247 ton of Fe.

Finally, we shall determine the tons of hematite (Fe₂O₃) needed to produce 49 tons of Fe. This can be obtained as follow:

From the balanced equation above,

0.000353 ton of Fe₂O₃ reacted to produce 0.000247 ton of Fe.

Therefore,

X ton of Fe₂O₃ will react to produce 49 tons of Fe i.e

X ton of Fe₂O₃ = [tex]\frac{0.000353 * 49}{0.000247} \\\\[/tex]

X ton of Fe₂O₃ = 70 tons

Thus, 70 tons of hematite (Fe₂O₃) is needed to produce 49 tons of Fe.

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Plz help me plz will give Brainly

Answers

Explanation:

a brittle, High melting solid : option B (MgCl2).

1) H2S

2) H2O

3) I2

weakest to strongest.

hope this helps you.

PLEASE HELP!!!!! WILL GIVE BRAINLIEST!!!!

Answers

The answer should be A

VisibleVisible wave length visible wavelength of light that are emitted by Adams can be used to get Nate explosive devices remotely

Why is the periodic table not arranged by atomic weight and instead arranged by atomic number?

Answers

The chemical properties are mainly dependent on the electrons, or in some cases the charge of the protons, which is independent of the number of neutrons.So,they are arranged by increasing atomic number…
Atomic weight doesn't increase in a constant manner with respect to elements increase in atomic number.Where as while taking about atomic number it increases in a specific manner so it's easy to arrange a periodic table .

At before Duberinor,Mendeleev tried to use atomic weight but they failed .

PLEASE EXPLAIN I KNOW THE ANSWER I NEED AN EXPLAINATION

The potential energy as a function of internuclear distance for three diatomic molecules, X2, Y2, and Z2, is shown in the graph above. Based on the data in the graph, which of the following

Answers

From the graph shown, Y2 = N2, X2 = O2, Z2 = H2.

When atoms of elements are at a large distance from each other, the potential energy of the system is high. However, as the atoms approach each other, the potential energy of the system decreases steadily. The closer the atoms come to each other, the lower the potential energy. This implies that potential energy is proportional to bond length.

Since N2 has a shorter bond length and higher energy, Y2 must be N2. The bond energy of hydrogen is small hence H2 must be X2. The bond energy of a double bond is intermediate between that of a single and triple bond hence Z2 must be O2.

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Guy’s pleaseeee help

Answers

Answer:

A. All isotopes have no charge

Two carbon atoms (Group 14) bond with two hydrogen atoms (Group 1) to form acetylene (C2H2). How would each carbon atom in acetylene bond?(1 point)

A) Each carbon atom would share one pair of electrons with hydrogen and three pairs with the other carbon atom.

B) Each carbon atom would share one pair of electrons with hydrogen and one pair with the other carbon atom.

C) Each carbon atom would share one pair of electrons with the other carbon atom and three pairs with each hydrogen atom.

D) Each carbon atom would share one pair of electrons with the other carbon atom and two pairs with each hydrogen atom.

Answers

A because I took the test and

PLS I NEED HELP QUICKKKKK

Match each example to the type of wave.

B. Longitudinal wave
A. Transverse wave
C. Combination of longitudinal and transverse wave
D. Infrared wave
E. Radiant energy
F. Microwaves
G. Ultraviolet waves

Answers

Answer: These are all examples of the waves you listed

B- Soundwave, ultrasound waves

A-Surface ripples on water

C- water waves

D-The heat that we feel from sunlight, a fire, a radiator or a warm sidewalk is infrared.

E-The heat emitted from a campfire.

F-Long Distance Wireless Transmission. Most wireless transmission systems are based on microwave technology.

G- Disinfectants

Explanation:

Hope this helps!!

Have a nice day!

A(1,2),B(1,4),C(6,2),

Answers

Answer:

????

Explanation:

where's the question


1. What is the shape of an organic molecule containing a triple bond with respect to the carbons on either side of the bond?
Explain your answer

Answers

Answer:

The alkyne is linear

Explanation:

Any molecule with a triple bond is considered an alkyne. In regards to the shape, because carbon can only bond to 4 different atoms at once a triple bond fills in 3 of the required 4 atoms needed to reach the molecules ground state (when it's most stable). The more electrons shared between atoms, the shorter the bond will be which results in a stronger and more linear line. Keep in mind a quadruple bond is not possible between carbons as of now.

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