Select the correct answer.
For Al, its atomic number is 13 and its mass number is 27. How many neutrons does it have?
Ο Α. .
13
ОВ.
14
26
OD
27
O E
40

Answers

Answer 1

Answer:

B.) 14

Explanation:

27-13=14 neutrons


Related Questions

When you work out your cells need

Answers

Answer:

Waterrrr

Explanation:

H2O

Answer:

Muscle contraction

Explanation:

According to the new study, exercise improves muscle health by renewing its cellular powerhouse: the mitochondria. Mitochondria are crucial to the good functioning of our bodies, as well as to our overall health and longevity. These tiny parts of the cell turn the food we eat into energy.

How do you decrease the amount of energy storage molecules there are in an ecosystem?
a) increase sunlight
b) decrease sunlight
c) burn dead matter
d) bury dead matter
e) trap carbon dioxide

Answers

Decreasing sunlight will decrease the amount of energy storage molecules in an ecosystem.

What is Photosynthesis?

This is the process in which green plants manufacture food in the presence of sunlight. Primary producers are involved in this process of providing energy to the ecosystem.

This therefore means that a decrease in sunlight means a decrease in photosynthesis and energy production.

Read more about Photosynthesis here https://brainly.com/question/19160081

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Ethanol is a common laboratory solvent and has a density of 0.789 g/mL. What is the mass, in grams, of 133 mL of ethanol?

Answers

Given:

[tex]V = \text{133 mL}[/tex]

[tex]\rho = \text{0.789 g/mL}[/tex]

Required:

[tex]m[/tex]

Solution:

[tex]\rho = \frac{m}{V}[/tex]

[tex]m = \rho V[/tex]

[tex]m = (\text{0.789 g/mL})(\text{133 mL})[/tex]

[tex]\boxed{m = \text{105 g}}[/tex]

Ethanol is a common laboratory solvent and has a density of 0.789 g/mL.  105g is the mass, in grams, of 133 mL of ethanol.

What is mass?

In physics, mass is a quantitative measurement of inertia, a basic characteristic of all matter. It essentially refers to a body of matter's resistance to changing its speed or location in response to the force that is applied. The change caused by a force applied is smaller the more mass a body has.

The kilogram, which would be specified as equivalent to 6.62× 10³⁴ joule second in terms of Planck's constant, is the unit of mass inside the International Units System (SI).

density = mass / volume

mass =density× volume

         = 0.78× 1.33

         =105g

Therefore, 105g is the mass.

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Which statement describes a homogeneous catalyst?
do
It is in a gaseous phase only. It is in the same phase as the reactants.
It is completely consumed by reactants.
It forms different products than the uncatalyzed reaction forms.

Answers

A homogeneous catalyst is in the same phase as the reactants.

The statement which is  given below describe a homogeneous catalyst.

"It is in the same phase as the reactants"

What is homogeneous catalyst?

The catalyst which have similar phase to the reactant of the reaction is called homogeneous catalyst.

Mostly in  homogeneous catalyst, catalyst present in liquid form.

To learn more about homogeneous catalyst here.

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In the process of photosynthesis, plants take in carbon dioxide (CO2) from the atmosphere and water (H2O) from the soil. Using the energy of sunlight, plants build molecules of glucose (C6H12O6) and oxygen (O2).

Select one:

a.
Plants absorb Carbon Dioxide which increases the amount of carbon in the atmosphere.

b.
Plants produce Carbon Dioxide which increases the amount of carbon in the atmosphere.


c.
Plants absorb Carbon Dioxide which reduces the amount of carbon in the atmosphere.


d.
Plants produce Carbon Dioxide which reduces the amount of carbon in the atmosphere.

Answers

Answer:

C

Explanation:

thts the right answwer im sure

Answer:

C

Explanation:

They take in carbon dioxide and make an oxygen. That's why they are encouraging people to plant. Less CO2 more oxygen

The tablets were crushed, and 4.9993 g of the powder was transferred to a beaker and reacted with HCl. After filtration, the filtrate was transferred to a 100-mL volumetric flask and diluted with water. 20.00 mL of this stock solution were combined with 0.2 M Na3PO4. The resulting precipitate weighed 0.3451 g after drying. Calculate the moles of BiPO4 precipitated, the moles of Bi3 in the stock solution, and the mass of BSS per tablet.

Answers

Answer:

Explanation:

From the information given:

Mass of BiPO₄ = 0.3451 g

Number of moles of BiPO₄ = [tex]0.3451 \ g \ BiPO_4 \times \dfrac{1 \ mol \ BiPO_4}{303.95 \ g \ BiPO_4}[/tex]

[tex]= 0.001135 \ mol[/tex]

The number of moles of Bi³⁺ in 20.00 mL is:[tex]= 0.001135 \ mol \ BiPO_4 \times \dfrac{1 \ mol \ of \ Bi^{3+}}{1 \ mol \ BiPO_4}[/tex]

=  0.001135 mol of Bi³⁺

The number of moles of Bi³⁺ in 100 mL stock solution

[tex]= 0.001135 \ mol \ Bi^{3+} \times \dfrac{100 \ mL}{20.0 \ mL}[/tex]

[tex]= 0.005675 \ mol[/tex]

Mass of BSS in 4.9993 g tablets

[tex]m = 0.005675 \ mol \ Bi^{3+} \times \dfrac{1 \ mol \ BSS}{1 \ mol \Bi^{3+}} \times \dfrac{362.1 \ g \ BSS}{1 \ mol \ BSS}[/tex]

m = 2.055 g BSS

Mass of BSS in 5.0103 g (5 tables)

[tex]m = 2.055 g \ BSS \times \dfrac{5.0103 \ g}{4.9993 \ g}[/tex]

= 2.06 g

The mass of BSS per tablet is [tex]=\dfrac{2.06 \ g}{5 \ tablet}[/tex]

= 0.412 g BSS/ tablet

Please help me l don’t understand please !!!!!!

Answers

Answer: C

Explanation:

he never had evidence in the first place that was nearly enough.

Which expression represents the concentration of OH– in solution?
a. 10–14 / [H3O+]
b. [OH–] / 10–14
c. 10–14 – [H3O+]
d. 10–14 x [H3O+]

Answers

10^-14 / [H3O+]
Explanation:
Hydronium (H3O+) and hydroxide ions (OH-) are both present in pure water and in all aqueous solutions.
Their respective concentrations in water are 10^-7 M each and are inversely proportional to each other as given by the ion product of water, Kw.
Kw = [H3O+][OH−]
Where Kw = 1.0 * 10^-14,
[H3O+] = concentration of hydronium ions
[OH-] = concentration of hydroxide ions
Therefore, [OH-] = Kw / [H3O+]
[OH-] = 10^-14/[H3O+]

What are the two types of bonding we have studied?

a. Metallic and covalent

b. Covalent and ionic

c. lonic and metallic

d. Molecular and metallic

Answers

Covalent and ionic.

Which of the following are diatomic elements? Select all that apply.
A.Hydrogen
B.Boron
C.Bromine
D.Iodine

Answers

Answer:

C

Explanation:

A diatomic element in that list is Bromine

A percent composition analysis yields
22.6% phosphorus (P) and 77.4%
chlorine (CI). What is the empirical
formula for the compound?
А
B
P2C17
PCI:

Answers

Answer:

PCl₃

Explanation:

To determine the empirical formula of a compound, we need to follow a series of steps.

Step 1: Divide each percent composition by the atomic mass of the element

P: 22.6/30.97 = 0.729

Cl: 77.4/35.45 = 2.18

Step 2: Divide all the numbers by the smallest one, i.e. 0.729

P: 0.729/0.729 = 1

Cl: 2.18/0.729 ≈ 3

The empirical formula of the compound is PCl₃.

what is the most important part of solution preparation​

Answers

Answer:

id k exactly what your asking

Explanation:

What is the hybridization of the central atom in CO2? Hybridization = What are the approximate bond angles in this substance? Bond angles = fill in the blank 2

Answers

Answer:

sp

Explanation:

Hybridization is the combination of atomic orbitals to yield equivalent hybrid orbitals of appropriate energy which can participate in bonding.

In every compound there is a central atom. The central atom is usually the least electronegative atom in the molecule. In this case the least electronegative atom in the molecule is carbon.

The bond between carbon and oxygen in CO2 is intermittent between a pure double and a pure triple bond. Hence, carbon is sp hybridized.

At which point on the roller coaster will the car have the greatest amount of Kinetic energy?

Answers

I’m going to say the answer is most likely X because memetic energy is energy being used at that moment. Because the coaster is going fastest at X we can assume that the answer is X

4
In the Hatom , what is the correct order (arrangement) of energy levels​

Answers

I believe you mean atom? 1s 2s 2p 3s 3p
This is the correct order of energy levels 1s<2s=2p<3s=3p=3d<4s=4p=4d=4f<5s=5p=5d=5f

LEVEL 3
Write the correct order
of letters to the finish line.
A E B E C
Example:
ABCGH
G
H
N
eza


Not correct

Answers

ANSWER - AEGHNZ (is that right?
look this is on quizlet

Which of the following correctly shows a synthesis reaction involving potassium?

A. Br2 + 2KI → I2 + 2KBr
B. 4K + O2 → 2K2O
C. 2KClO3 → 2KCl + 3O22KClO3 → 2KCl + 3O2
D. 2K2O → 4K + O22K2O → 4K + O2

Answers

Answer:

B. 4 K + O₂ → 2 K₂O

Explanation:

Which of the following correctly shows a synthesis reaction involving potassium?

A. Br₂ + 2 KI → I₂ + 2 KBr

No, this is a single displacement reaction, in which Br displaces I from its salt.

B. 4 K + O₂ → 2 K₂O

Yes, this is a synthesis reaction, in which 2 elements combine to form a compound.

C. 2 KClO₃ → 2 KCl + 3 O₂

No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.

D. 2 K₂O → 4K + O₂

No, this is a decomposition reaction, in which a big substance decomposes into smaller ones.

Basic Stoichiometry
Part 1: Mole ←→ Mass Conversions
Choose 2: Convert the following number of moles of chemical into its mass in grams.
1. 0.436 moles of (NH4)Cl = ______g
2. 0.50 moles of Ca(NO3)2 = ______g
Choose 2: Convert the following masses into their corresponding number of moles.
3. 23.5 g of NaCl = ______moles
4. 79.9 g of KMnO4 =______moles
5) The combustion of a sample of butane, C4H10 (lighter fluid), produced 2.46 grams of water.

Answers

Answer:

1. 23.3 g

2. 82 g

3. 0.402 mol

4. 0.506 mol

Explanation:

We can convert moles (n) to mass (m) using the following expressions that include the molar mass (M).

n = m/M

m = n × M

1. The molar mass of NH₄Cl is 53.49 g/mol.

m = 0.436 mol × 53.49 g/mol = 23.3 g

2. The molar mass of Ca(NO₃)₂ is 164.09 g/mol.

m = 0.50 mol × 164.09 g/mol = 82 g

3. The molar mass of NaCl is 58.44 g/mol.

n = 23.5 g/(58.44 g/mol) = 0.402 mol

4. The molar mass of KMnO₄ is 158.03 g/mol.

n = 79.9 g/(158.03 g/mol) = 0.506 mol

Methane and sulfur react to produce carbon disulfide (CS₂), a liquid often used in the production of cellophane.

2CH₄ + S₈ --> 2CS₂ + 4H₂S

Calculate the moles of H₂S produced when 2.25 mol S₈ is used.

Answers

Answer:

9 moles

Explanation:

The balanced chemical equation provided in this question is as follows:

2CH₄ + S₈ → 2CS₂ + 4H₂S

In accordance to the above balanced equation, 1 mole of sulphur (S8) produces 4 moles of hydrogen sulfide (H2S).

Therefore, if 2.25mol of S8 is used, 2.25 × 4 = 9 mol

9 moles of H2S is produced.

Plz help me I am timed!!

Answers

Answer:

What do you need help with

Explanation:

Explanation:

okay I'll help but whats the question

Tam a highly reactive alkali metal in period 3 with only one valence electron
O Sodium (Na)
Beryllium (Be)
Magnesium (Mg)

Answers

Answer:

Sodium (Na)

Helium

Magnesium (Mg).

Explanation:

From the periodic table, we will understand that the group 1 metals are the alkali metal. However, the period runs from left to right on the periodic table while the group runs from up to down in the periodic table. In period 3, the alkali metal present there with one valence electron in its outermost shell is sodium (Na).

The only noble gas exists in the last group, group zero of the periodic table. However, the only noble gas with two electrons in its outermost shell is called Helium

The ALkaline earth metals are group 2 metals. They are usually shiny metals and the ability to lose 2 electrons in their outermost electron shell. The alkaline earth metal located in period 3 is Magnesium (Mg).

Determine how many molecules are in 86L of carbon dioxide at STP?

Answers

Answer:How can you tell how much gas is in these containers?

Small gas tanks are often used to supply gases for chemistry reactions.  A gas gauge will give some information about how much is in the tank, but quantitative estimates are needed so the reaction will be able to proceed to completion.  Knowing how to calculate needed parameters for gases is very helpful to avoid running out too early.

Conversions Between Moles and Gas Volume

Molar volume at STP can be used to convert from moles to gas volume and from gas volume to moles.  The equality of 1 mole = 22.4 L is the basis for the conversion factor.

Sample Problem One: Converting Gas Volume to Moles

Many metals react with acids to produce hydrogen gas.  A certain reaction produces 86.5 L of hydrogen gas at STP.  How many moles of hydrogen were produced?

Step 1: List the known quantities and plan the problem.

Known

86.5 L H2

1 mol = 22.4 L

Unknown

moles of H2

Apply a conversion factor to convert from liters to moles.

Step 2: Calculate.

Explanation:

Please help with yes or no

Answers

All of them are yes

For each of the environments below: (1) identify your system and surroundings and (2) predict whether it would be endothermic or exothermic.a.Wood burningSystem:Surroundings:Enthalpy Change:b.Water freezingSystem:Surroundings:Enthalpy Change:c.Sweat evaporatingSystem:Surroundings:Enthalpy Change:d.Chemical hand-warmerSystem:Surroundings:Enthalpy Change:

Answers

Answer:

A) Wood burning

system : Wood.

surroundings : atmosphere

Enthalpy : Exothermic

B) Water Freezing system

System : Refrigerator

surroundings :  water in the refrigerator

enthalpy change : Endothermic

C) Sweat evaporating

System :  Human being

surroundings : Air nearby

Enthalpy change : exothermic

D) Chemical Hand-warmer

system : Hand warmer pack

Surroundings : human palms

Enthalpy Change : Exothermic

Explanation:

A) Wood burning

system : Wood

surroundings : atmosphere

Enthalpy : Exothermic

This system give away energy to its surroundings hence its enthalpy change is exothermic

B) Water Freezing system

System : Refrigerator

surroundings :  water in the refrigerator

enthalpy change : Endothermic

The system absorbs heat from what is put inside(surroundings ) of it hence this is na endothermic system

C) Sweat evaporating

System :  Human being

surroundings : Air nearby

Enthalpy change : exothermic

This is an exothermic reaction ( enthalpy change ) because the system gives out heat to the surrounding

D) Chemical Hand-warmer

system : Hand warmer pack

Surroundings : human palms

Enthalpy Change : Exothermic

There is movement of heat from the system to the surrounding hence it is an exothermic reaction

The acceleration of a baseball after it is hit by a bat depends on the mass of the ball and the net force on the ball. This example best illustrates which law?

a
Newton's law of universal gravitation.
b
Newton's first law of motion.
c
Newton's third law of motion.
d
Newton's second law of motion.

Answers

The answer is Newton’s second law because it’s force equals massxacceleration

plz, help me it's urgent

Answers

Answer:

Explanation:

A is solid, b is melting, c is freezing, d is liquid, e is evaporating, g is gas, and f is condensation.

Hello Mikaela!

Let's start from the top, letter G. Letter G should be gas. Letter F should be condensation. Letter E should be evaporation. Letter D should be liquid. Letter C should be freezing. Letter B should be melting. And letter A should be solid.

I really hope this helps!!

what statement is the best description of a chemical bond

Answers

Answer:

A chemical bond holds atoms together.

Cars are the leading cause of____

1. carbon dioxide
2. nitrogen oxide
3.carbon monoxide

pollution

Answers

Answer:

nitrogen oxide

Explanation:

leading cause of nitrogen oxide
not 100% sure

7th grade science lol help​

Answers

Answer:

The process you are referrring to is erosion.

Explanation:

Weathering would be the breaking down of rock/other land debris. Its more active counterpart would be erosion, wherein the process transports the bits of rock and minerals away. Hope it helps!

how is acid different from base​

Answers

Hehsnsgx d she. Wayy buy is s
As
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