answer this step by step pls

Answer This Step By Step Pls

Answers

Answer 1

Answer:

neutrons = mass number - atomic number

. = 39-19 =20


Related Questions

Which of the following is/are considered alcohols?
a CH3OH
b CH3CH2OH
C CH3CH2CH2OH
d All of the above

Answers

Answer: THE ANSWER IS D

Explanation:

an alcohol is a hydrocarbon chain with an hydroxyl group (OH)

A, B, AND C ARE ALL ALCOHOLS, SO THE ANSWER IS D

Atoms: SC.8.P.8.7

Match the definition to proper definition:

Term:

Definition:

1. Atoms

A.Positive subatomic particles found in the

nucleus of the atom

2. Neutron

B. Negative subatomic particle found in the cloud

3. Proton

C. Substance that has no electrical charge

4. Nucleus

D. Basic building block of all matter

5. Electron cloud

E. Substance that consists of only one type of ato,

6. Electrons

F. Center of an atom with a positive charge

G. Outside of the atom with a negative charge

7. Element

Answers

Answer:

1 = D

2 = C

3 = A

4 = F

5 = G

6 = B

7 = E

EASY QUESTION (PLEASE HELP THE INTERNET ISN'T SUCH A BIG HELP RIGHT NOW)
Things microscopes have helped scientists discover about cells.
(No links plz)

Answers

Answer:

Microscopes allowed scientists to observe Prokaryotic cells which make up Bacteria and Archaea.

for each type of geometry in the simulation, examine the resulting bond angles by clicking the show bond angles checkbox. based on your observations for each geometry, provide the bond angles at the indicated locations for the two-dimensional representations of the three-dimensional structures.

Answers

The bond angles in PCl5 are 90° and 180° respectively. The bond angle in NH4^+ is 109°.

Bond angles refer to the angle between two atoms bonded to the same central atom. Several factors such as electronegativity difference and presence or absence of lone pairs on the central atom all affect the bond angle.

For NH4^+, the indicated bond angle is 109° and the specie is tetrahedral. For the specie, SF6, the indicated bond angles are 90° and 180° respectively. For HCN, the indicated bond angle is 180°. For PCl5, the indicated bond angles are 90° and 180° respectively.

Learn more: https://brainly.com/question/2192784

how might rising atmospheric co2 concentrations lower the ph of the oceans?

Answers

Explanation:

As CO2 concentrations rise, excess CO2 is absorbed by the oceans. CO2 in the oceans can react chemically with water to form acid. ... The difference in pH units between two acidic solutions is three.

Review the information from the documents you read for this assignment. Use what you learned to answer the following question. What were the major effects of a dust storm? Give your answer in at least four sentences.

Answers

Answer:

what people experienced during a dust storm

how people reacted to a dust storm

what people did after a dust storm

Explanation:

i passed

Answer:

what people experienced during a dust storm

how people reacted to a dust storm

what people did after a dust storm

Explanation:

Elements in the same period in the same periodic table have the same ____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________

Answers

Elements in the same period have the same number of electron shells; moving across a period (so progressing from group to group), elements gain electrons and protons and become less metallic. This arrangement reflects the periodic recurrence of similar properties as the atomic number increases.

PLEASE MARK ME BRAINLIEST ANSWERER

PLZ HELP i need it now

Answers

If maybe you can state what you’re writing about

Study the chemical equation.
Na + Cl2 → NaCl
Is the chemical equation properly balanced?

Answers

no it should be Na2Cl

convert 120 mm to feet

Answers

Answer:

0.393701

Explanation:

0.393701 !!!!!!!!!!!!!!!!!!!

how many electrons need to be lost or gained by Ca to attain noble gas electron configuration?

Answers

Answer:

six electrons need to be gained

Explanation:

Calcium has two valence electrons. To have a stable amount of valence electrons, or to attain noble gas electron configuration, an element needs to have eight valence electrons. Now, it's just a simple math problem. How many  more valence electrons does calcium need to get to eight? It needs six, since eight minus two is six.

Hopefully that's helpful! :)

Question 1 (2 points)
Which option can be classified as a pure substance?

Question 1 options:

heterogenous mixture


solution


homogenous mixture


compound

Question 2 (2 points)
Law of conservation of mass states that:

Question 2 options:

matter is destroyed


matter does not change


matter is neither created nor destroyed


matter is created

Question 3 (2 points)
What is a property of bases?

Question 3 options:

all of the above


Sour taste


Slippery touch


Ability to form hydronium ions+

Question 4 (2 points)
Which property do solutions with low pH values have?


What does it mean to have a neutral pH? - Aseptic Health

Question 4 options:

have a -OH group


feels slippery


turns litmus paper blue


tastes sour

Question 5 (2 points)
How do the products of chemical reactions compare to their reactants?

Question 5 options:

The products often have completely different properties than the reactants.


The products are usually more toxic than the reactants.


The products usuallyhave more mass than the reactants.


The products usually have more atoms than the reactants.

Question 6 (2 points)
Which of the following is an example of a physical change?

Question 6 options:

Water freezing into ice.


A piece of wood burning.


A toy car rusting.


Zinc producing hydrogen gas when mixed with water.

Question 7 (2 points)
What might happen if you mixed a strong acid with an equally strong base?

Question 7 options:

You would see an explosive chemical reaction.


The base would destroy the acid.


You'd wind up with a pH-neutral salt and water.


The acid would destroy the base.

Question 8 (2 points)
In the equation shown, what are the reactants?

2H2+O2àH2O

Question 8 options:

Hydrogen and oxygen molecules (2H2 and O2 )


Ice crystals


Hydrogen atoms (H)


Water molecules (H2O)

Question 9 (2 points)
Which phrase most accurately describes a chemical change?

Question 9 options:

A change in form


A change in taste


A change on the molecular level


A change in appearance

Question 10 (2 points)
What does it mean when there is a physical change?

Question 10 options:

A new substance has been formed.


Matter has changed from one substance into a new substance.


Matter has changed size, shape or form


Matter has changed on the molecular level.

help pls ill give 20 points!

Answers

Answer:

I didn't KNOW WHAT IS THE ANSWWR OF YOUR QUISTION IM SO SORRY

Explanation:

I WANT TO INTRODUCE SELF TO YOU CAN I

describe the development of the theory of atomic structure
this question is worth 6 marks

Answers

The atomic theory, which holds that matter is composed of tiny, indivisible particles in constant motion, was proposed in the 5th cent. BC by the Greek philosophers Leucippus and Democritus and was adopted by the Roman Lucretius. However, Aristotle did not accept the theory, and it was ignored for many centuries.

how many valence electrons are there in a magnesium atom?

Answers

Answer:

Magnesium has 2 valence electrons.

Determine the pH of 7.53 x 10-4 mol/L calcium hydroxide solution

Answers

Answer:

pH = 11,17

Explanation:

[tex][OH^{-} ] = \frac{n_{OH^{-} } }{V} = \frac{2n_{Ca(OH)_{2} } }{V} = 2[ Ca(OH)_{2} ]\\[/tex]

[tex]Ca(OH)_{2}[/tex]    →   [tex]Ca^ {2+}[/tex]        +     [tex]2OH ^ -[/tex]

[tex]7,53.10^-4[/tex]   → [tex]7,53.10^-4[/tex]   →    [tex]1,506^-3[/tex]

pOH = -log [[tex]OH^-[/tex]] = [tex]-log 1,506^{-3}[/tex] ≈ 2,822

pH = 14- pOH = 14-2,822 = 11,178

why are there no elementary substances that have the ionic bond?

Answers

This problem is asking for the reason behind the nonexistence of elementary substances with ionic bonds. First of all, it is necessary to bear to mind that the definition of the type of bond in a compound depends on the difference electronegativity that is present between two of the atoms composing it.

For instance, in binary salts, such as KCl, NaCl, KBr and so on, we are able to know these are all ionic because they are composed by a metal and a nonmetal, which have the smallest and largest electronegativities, so that the difference electronegativity is large enough to produce an ionic bond.

In contrast, elementary susbtances, such as liquid bromine (Br2) and gases such as H2, N2, Cl2, F2 and O2, since they are all nonmetals and the same type, the electronegativity difference will be 0 and therefore, they will not be ionic but covalent.

Learn more:

https://brainly.com/question/15105831https://brainly.com/question/14509196

what is the mass percent of hydrogen in water

Answers

Answer:

11.11%

Explanation:

The percentage of an element in a compound is 100 times the fraction, so for water the mass percent hydrogen is 11.11%

Hope this helps :)

What is the average acceleration of the car between 24 and 40 seconds? Include the correct units.

Answers

Answer:

16

Explanation:

40 - 24  16

What are the four groups of carbon compounds found in living things?

Answers

carbohydrates, lipids, proteins, and nucleic acids

Darwin observed __________________ types of mockingbirds and finches lived in different island environments.

Answers

Answer:    

Darwin observed   many  different   types of mockingbirds and finches lived in different island environments.

JWhat type of evidence is gathering information through your senses or using scientific tools?

Predictions
Results
Scientific research
Observations

Answers

Observations etc etc

A clasping handshake may be used as an analogy for an enzyme-catalyzed reaction because it represents the specific manner in which an enzyme ________. folds to form secondary and tertiary structures interacts with water binds substrate is denatured by low pH

Answers

A clasping handshake is similar to the way in which enzymes bind to substrates in enzyme-catalyzed reactions.

Enzymes are biological catalysts that speed up the rates of biological reactions by lowering the minimum energy required by reactants in order to arrive at products.

Enzymes are able to achieve this feat by substrate-enzyme binding. The substrate binds to the enzyme in its active site, becomes products, and the products are released from the active site of the enzyme. Thus, the enzyme is free for the binding of another substrate.

More on enzyme-catalyzed reactions can be found here: https://brainly.com/question/6658074


What do all atoms in a period (horizontal rows) have in common?

Answers

Answer:

All of the elements in a period have the same number of atomic orbitals. For example, every element in the top row (the first period) has one orbital for its electrons. All of the elements in the second row (the second period) have two orbitals for their electrons.

hope this helps

Explanation:

Elements in the same period are those that are in a single horizontal line from left to right. They do not share the same type of chemical reactivity as seen in groups. They only real thing that these elements share in common is the same principal quantum number, or main energy shell.

the electron configuration of an element describes _____.

Answers

Answer:

here

Explanation:

This is the electron configuration of the element carbon.


11) When sodium metal is subjected to violet light, it causes the photoelectric effect. However, red light does not affect
the sodium. Explain this phenomena.

Answers

The maximum wavelength for which photoelectric effect occurs in sodium is 400 nm.

Photoelectric effect has to do with the ejection of electrons from a clean metal surface when energy is supplied in the form of light. All wavelengths of light are not capable of achieving photoelectric effect.

There exists a maximum wavelength that the incident rays must posses in order for photoelectric effect to occur. The maximum wavelength for which photoelectric effect occurs in sodium is 400 nm.

The wavelength of red light is around 625 - 740 nm which is far longer than the wavelength of violet light which is around 380 - 425 nm. Hence, when sodium metal is subjected to violet light, it causes the photoelectric effect but red light does not affect the sodium metal.

Learn more: https://brainly.com/question/865531

What were the first 5 planets that were observed? Why were those the only ones? Help pls!

Answers

Mercury Venus mars Jupiter Saturn

In the chloroplast, energy in sunlight is passed around different chlorophyll molecules until it reaches a specific chlorophyll molecule that can transfer energy in sunlight to an energized electron. This chlorophyll molecule is called the accessory pigment. electron-carrier molecule. nucleus. photoelectric point. reaction center.

Answers

Answer:In the chloroplast, energy in sunlight is passed around different chlorophyll molecules until it reaches a specific chlorophyll molecule

Explanation:

Answer: In the chloroplast, energy in sunlight is passed around different chlorophyll molecules until it reaches a specific chlorophyll molecule

what do you mean by decimal number system

please give answer​

Answers

The decimal number system also called Hindu-Arabic number system or Arabic number system, comprises digits from 0-9 that are 0, 1, 2, 3, 4, 5, 6, 7, 8 & 9.

Which of the following is the best definition of deposition in geology?(1 point)

A:the creation of volcanic rock when liquid magma hits the ocean and cools

B:the mixing of many layers of sediment by wind, water or ice


C:laying down of sediment in layers carried by wind, water or ice


D:the creation of any metamorphic rock

Answers

Answer:

Deposition is the laying down of sediment carried by wind, flowing water, the sea or ice. Sediment can be transported as pebbles, sand and mud, or as salts dissolved in water.

Lead has a density of 11.29 g/mL. If you had 186 g of lead, what would its volume be?

Answers

I think you just do 11.29 multiplied by 186 since to find density you divide mass by volume. So 186 divided by x is 11.29. So in conclusion the volume would be 2,099.94mL
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