How many electrons are in an ion of calcium (Ca2+)?
A. 2
B. 18
C. 0
D. 22

Answers

Answer 1
B 18 is the answer ......

Related Questions

Rahul sits in a chair reading a book. Which force is equal to the force Rahul exerts on Earth?

Rahul’s weight
Rahul's mass
the sum of the weights of Rahul and the book
the sum of the weights of the chair, Rahul, and the book

Answers

Answer:

rahul's weight

Explanation:

internet

The force is equal to the force Rahul exerts on Earth is Rahul's weight.

What is Force?

Force is that thing which cause a change in the motion of an object

What is force Rahul?Since Rahul sits on the chair, his weight exerts a downwards force towards the Earth which is the attraction of the Earth on Rahul. Now, Rahul also exerts a force of attraction on the Earth which is also equal to his weight, since according to Newton's third law which states that for every action, there is an equal and opposite reaction.

So, Rahul exerts a force on the Earth equal to his weight.

Thus, the force is equal to the force Rahul exerts on Earth is Rahul's weight.

Learn more about force here:

https://brainly.com/question/25239010

What product is formed when sodium and chlorine undergo a synthesis reaction? sodium chlorite
sodium chlorate
sodium and chloride
sodium chloride

Answers

Sodium chloride is the answer
Sodium chloride is formed

On the bottom beam of the triple beam balance, each small division stands for
A.) one centimeter
B.) one milliliter
C.) one gram
D.) one-tenth of a gram

Answers

Answer:

Hello There!!

Explanation:

I believe the answer is D.) one-tenth of a gram.

hope this helps,have a great day!!

~Pinky~

[tex]\huge{\textbf{\textsf{{\color{navy}{An}}{\purple{sw}}{\pink{er}} {\color{pink}{:}}}}}[/tex]

D.) one-tenth of a gram

Thanks.Hope it helps.

Select all of the HOMOGENEOUS mixtures from this list (click all that apply).

A. Paint
B. Chili
C. Blood
D. Soil
E. Salt water

Answers

Answer:

E is answer

Explanation:

salt water is the answer

Answer:

E.Salt water

Explanation:

Salt water  is  a homogeneous because the dissolved salt is evenly distributed throughout the entire salt water sample. The amount of salt in the salt water can vary from one sample to another.

Please help this is due today! 5-11-2021

Observe the chemical reaction below, and identify if the equation is balanced or not. If it is not balanced, then what coefficient should you place for the reactants and products? Justify with scientific reasoning.

Mg + O2---------> MgO

Make sure to include the following details in your answer in complete sentences:

- Is the chemical reaction balanced?

- Is it following the law of conservation of mass, why is not following?

- What can you do to make sure that the equation becomes balanced and follow the law?

Answers

Answer:

- The chemical reaction is not balanced. There is two oxygens on the reactant's side while there's only one oxygen on the products side.

- I would not say it's following the law of conservation of mass as it's not a balanced equation.

- To balance this equation, you would need to add the coefficient of '2' to Magnesium (Mg) on the reactants side, and add the coefficient of '2' to the products side.  This would make it so that there's 2 Mg's and 2 O's on both the reactant's side and products side.

edit: I hope this helped you in some way. ^^

Describe how nucleic acid basis pair up

Answers

The rules of base pairing (or nucleotide pairing) are: A with T: the purine adenine (A) always pairs with the pyrimidine thymine (T) C with G: the pyrimidine cytosine (C) always pairs with the purine guanine (G)

The nucleotides in a base pair are complementary which means their shape allows them to bond together with hydrogen bonds. The A-T pair forms two hydrogen bonds. The C-G pair forms three. The hydrogen bonding between complementary bases holds the two strands of DNA together.

Which of the following is an example of a molecular element?

a.NaCl b. CO2 c. Na d. O2

Answers

Answer:

oxygen (O2) is a molecular element

Explanation:

Molecular compound are chemical compounds that take the form of discrete molecules.

atomic element is an element which occurs independently as atoms and can react with other elements to form a compound

Ionic compounds are the compound which on dissolution form ions in solution

Mixture is the composition of different compounds

1. What is the new volume of a sample of neon if 5.23 L of the gas, which was originally at 214 mmHg, is compressed until the pressure increases to 796 mmHg?
2. When a balloon containing 635 mL of air is taken from sea level (at standard pressure) to a higher altitude, the balloon expands to 829 mL. What is the air pressure at this new altitude (in atm)?
3. A 465 mL sample of gas at 55°C is cooled to standard temperature (0°C). What is its new volume?
4. To what Celsius temperature does 750. mL of gas originally at −12°C need to be heated to bring the volume to 2.10 L?
5. The pressure in a car tire is 217 kPa at 24°C. After being driven on a hot summer day, the pressure in the tire increases to 258 kPa. What is the Celsius temperature of the air in the tire?
6. A gas sample originally at −39°C is heated to standard temperature (0°C), at which point its pressure is measured to be 808 mmHg. What was the original pressure of the gas?
7. A 400. mL sample of gas at 15°C and 113 kPa is heated to 227°C while expanding into a 900. mL container. What is the new pressure of the gas in kPa?
8. 2.50 g of CO2 gas is confined in a rigid cylinder at a pressure of 4.65 atm. If 0.42 g of gas is released from the cylinder, what is the new pressure?
Please help I'm so bad at chemistry

Answers

Here are attached photos, I don’t think they ar links, lmk if they don’t work

in the answering section it didn’t show me the full question so I only saw a little of question 5. Hopefully you get the idea of how to identify which equations to use tho! Good luck!

Concerning the disposal of materials at the end of the experiment, which methods are safe? Check all that apply.


[ANSWERS]


B. Dispose of pH paper in the trash.


C. Dump the cabbage indicator solution down the drain.


D. Ask your teacher to neutralize the acids and bases before disposal.

Answers

Answer:

B. Dispose of pH paper in the trash.

C. Dump the cabbage indicator solution down the drain.

D. Ask your teacher to neutralize the acids and bases before disposal.

Explanation:

Safe disposal of waste means disposal of waste in such a way that it does not pose a threat to the environment.

When pH paper is properly disposed in the trash, it does not constitute any risk to the environment.

When a cabbage indicator solution is disposed down the drain it does not contaminate the environment. It moves directly into the sewers and is properly disposed.

When acids and bases are properly neutralized before disposal, they don't lead to acid or base contamination of the environment.

Each element emits its own unique wavelength of light which can be used to determine the identity of that element. The packet or light wave emitted is called a

Answers

Answer:

Photon

Explanation:

The simplest description of a photon is to consider it as a bundle of electromagnetic energy.

In the context of wave - particle duality, light is considered sometimes as a particle. Each bundle of the particles of light wave is called a photon of light.

The wavelength of a photon of light emitted by an element can be used as a tool to identify that particular element.

Hot water is poured into four cups made of different materials (foam, glass, metal, plastic).After one minute, which will feel the warmest when you touch the OUTSIDE of the cup?

Answers

The answer to this is metal

Answer:

Metal

Explanation:

Foam, glass, and plastic don't absorb as much heat as metal does.

A2 Could you remove the iron from the iron sulfide using
magnet?
Explain your answer.

Answers

the iron and sulfur still behave like iron and sulfur in the mixture, but iron sulfide has different properties from both iron and sulfur.

you can separate the iron from the mixture using a magnet, but this does not work for iron sulfide

Name the process by which oxygen moves from alveoli to blood

Answers

diffusion...........the blood through the capillaries lining the alveolar walls. Once in the bloodstream, oxygen gets picked up by the hemoglobin in red blood cells.

Find the molality of a solution of 58.5 g NaCl dissolved in 0.556 kg of water

Answers

Answer:lmk

Explanation:

1) Escribe oraciones coherentes que incluyan los siguientes términos con los conceptos correspondientes:

CARBÓN-PETRÓLEO-GAS NATURAL-RECURSO NO RENOVABLE-

COMBUSTIBLES FÓSILES-HIDROCARBUROS-RESERVAS-CONTAMINACIÓN-

MAREAS NEGRAS

Answers

La respuesta correcta para esta pregunta abierta es la siguiente.

Estas son las oraciones apropiadas.

El carbón, el petróleo, y el gas natural son recursos naturales no renovables.

Estos generadores naturales de energía son considerados combustibles  fósiles que produce la mayor parte de hidrocarburos que se usan en el mundo. Sin embargo, estas reservas energéticas se están agotando porque son recursos naturales no renovables. Además, estos combustibles son altos generadores de contaminación como es el caso de las mareas negras.

Independientemente de estas ideas, es apropiado decir que los combustibles fósiles han sido fuertemente cuestionados por los ambientalistas y los científicos porque son causantes del llamado calentamiento global y del cambio climático.

Por esa razón, la sociedad y los expertos ambientalistas están pidiendo que los gobiernos comiencen a utilizar más energías alternativas y renovables como la energía solar y las turbinas de viento o energía eólica.

Which of the gases in air are compounds? Explain how you can tell.

Answers

Answer:

[tex]\huge \underline\bold\red{Answer}[/tex]

The air in the atmosphere consists of nitrogen, oxygen, which is the life-sustaining substance for animals and humans, carbon dioxide, water vapour and small amounts of other elements (argon, neon, etc.). Higher in the atmosphere air also contains ozone, helium and hydrogen.

Answer:

The air in the atmosphere consists of nitrogen, oxygen, which is the life-sustaining substance for animals and humans, carbon dioxide, water vapour and small amounts of other elements (argon, neon, etc.). Higher in the atmosphere air also contains ozone, helium and hydrogen.

5. How would you calculate the pH (NOT POH) of a base when given

the concentration of [OHJ?

Answers

Answer:

pOH = -log₁₀ [OH-]

pH = 14 - pOH

Explanation:

First of all, calculate the value of pOH from  the hydroxide concentration do this using the equation below;

pOH = -log₁₀ [OH-]

After obtaining the pOH, calculate pH using the equation below:

pH + pOH = 14

pH = 14 - pOH

which process is a chemical change​

Answers

Burning a match, In chemistry, there are two basic types of change, these are physical and chemical change. In physical change, no new material is formed and the process is reversible while in chemical change new materials are formed and the process is irreversible

Hydrogen gas can be produced in the laboratory by the reaction of magnesium metal with hydrochloric acid, according to the following equation:
Mg(s) + 2HCl(aq) --> MgCl2(aq) + H2(g)

a. How many grams of hydrogen can be produced when 4.00 g of HCl is added to 3.00 g of Mg?

b. Assuming STP, what is the volume of this hydrogen?

Answers

Answer: 0.11 g H2

Explanation: just took test and got it right

Given a solution with a hydrogen ion concentration of 9.9 x10-13 M, calculate the
pОН. .

Answers

Answer: The pOH value is 2.

Explanation:

Given: [tex][H^{+}] = 9.9 \times 10^{-13} M[/tex]

pH is defined as the negative logarithm of hydrogen ion concentration.

Hence, pH of the given solution is calculated as follows.

[tex]pH = -log [H^{+}]\\= - log (9.9 \times 10^{-13})\\= 12[/tex]

The relation between pH and pOH is as follows.

pH + pOH = 14

Therefore, pOH is calculated as follows.

pH + pOH = 14

12 + pOH = 14

pOH = 14 - 12

= 2

Thus, we can conclude that the pOH value is 2.

(reporting links) brainly
Amebic dysentery is a disease caused by organisms that live in dirty water. Which is most likely to prevent an epidemic of amebic dysentery?


A. vaccination of the population

B. purification of drinking water

C.public education on the importance of washing hands

D.restriction on travel to places with amebic dysentery

Answers

Answer:

The answer would have to be public education on the importance of washing hands.

Explanation: Washing hands is always one of the best ways to prevent a contagious disease.

How many joules of heat are needed to raise the temperature of 62.0 g of ethylene glycol from 13.1 C to 40.5C?

Answers

Answer:

Q = 4133.2 J

Explanation:

Hello there!

In this case, since these calorimetry problems are based off the following heat equation involving heat (Q), mass (m), specific heat (C) and temperatures (T):

[tex]Q=mC(T_2-T_1)[/tex]

Thus, we plug in the given variables to obtain:

[tex]Q=62.0 g*2.433 \frac{J}{g\°C}* (40.5\°C-13.1\°C)\\\\Q=4133.2J[/tex]

Regards!

If an atom has 8 electrons and 8 protons and 9 neutrons then what is it's net charge?"
choices:
0
1+
1-
2-

Answers

The answer is 0. Protons have a +1 charge and electrons have a -1 charge. Neutrons are neutral.

Give examples of how land resources are used in a city setting

Answers

Answer:

Land resources such as gravel and bedrock are used to construct buildings, roads, and sidewalks. Land is also where city structures—such as buildings, roads, and sidewalks—are constructed. People use land resources such as bedrock and aggregate to construct buildings, roads, and sidewalks.

I hope this answer helps

Iodine-131 half life 8.040 how long will it take for a 40 gram sample of iodine-131 to decay to 0.75 grams

Answers

Answer:

See explanation below

Explanation:

To get this, we need to apply the general expression for half life decay:

N = N₀e(-λt)    (1)

Where:

N and N₀ would be the final and innitial quantities, in this case, masses.

t: time required to decay

λ: factor related to half life

From the above expression we need λ and t. To get λ we use the following expression:

λ = t₁₂/ln2   (2)

And we have the value of half life, so, replacing we have:

λ = 8.04 / ln2 = 11.6

Now, we can replace in (1) and then, solve for t:

0.75 = 40 exp(-11.6t)

0.75 / 40 = exp(-11.6t)

ln(0.01875) = -11.6t

-3.9766 = -11.6t

t = -3.9766 / -11.6

t = 0.34 days

Kinetic energy is a measure of a particles what?

A: Size
B: Motion
C:Color
D:Weight

Answers

B is the answer because it is

How many moles of O₂ are needed to react completely with 35.0 mol of FeCl₃?


4FeCl3+3O2->2Fe2O3+3Cl2


The 2 for the second half of the equation is not a coefficient it’s supposed to be for 2Fe2 Not 2O3.

26.3 mol

46.7 mol

23.3 mol

10.0 mol

Answers

Answer:

26.3 mol O₂

Explanation:

Step 1: Write the balanced equation

4 FeCl₃ + 3 O₂ ⇒ 2 Fe₂O₃ + 6 Cl₂

Step 2: Establish the appropriate molar ratio

According to the balanced equation, the molar ratio of FeCl₃ to O₂ is 4:3.

Step 3: Calculate how many moles of O₂ are needed to react completely with 35.0 mol of FeCl₃

We will use the previously established molar ratio.

35.0 mol FeCl₃ × 3 mol O₂/4 mol FeCl₃ = 26.3 mol O₂

Balloon has a volume of 600-ml at temperature of 360 K. If the temperature of
the balloon drops to 250 K, find the volume

Answers

Answer:

V₂ ≈416.7 mL

Explanation:

This question asks us to find the volume, given another volume and 2 temperatures in Kelvin. Based on this information, we must be using Charles's Law and the formula. Remember, his law states the volume of a gas is proportional to the temperature.

V₁ / T₁ = V₂ / T₂

where V₁ and V₂ are the first and second volumes, and T₁ and T₂ are the first and second temperature.

The balloon has a volume of 600 milliliters and a temperature of 360 K, but the temperature then drops to 250 K. So,

V₁= 600 mL T₁= 360 K T₂= 250 K

Substitute the values into the formula.

600 mL /360 K = V₂ / 250 K

Since we are solving for the second volume when the temperature is 250 K, we have to isolate the variable V₂. It is being divided by 250 K. The inverse o division is multiplication, so we multiply both sides by 250 K.

250 K * 600 mL /360 K = V₂ / 250 K * 250 K 250 K * 600 mL/360 K = V₂

The units of Kelvin cancel, so we are left with the units of mL.

250 * 600 mL/360=V₂416.666666667 mL= V₂

Let's round to the nearest tenth. The 6 in the hundredth place tells us to round to 6 to a 7.

416.7 mL ≈V₂

The volume of the balloon at 250 K is approximately 416.7 milliliters.

How many moles is 8.3 x 10^12 atoms or particles of Br2
urgent

Answers

Explanation:

To find the number of moles in a substance given it's number of entities we use the formula

[tex]n = \frac{N}{L} \\[/tex]

where n is the number of moles

N is the number of entities

L is the Avogadro's constant which is

6.02 × 10²³ entities

We have

[tex]n = \frac{8.3 \times {10}^{12} }{6.02 \times {10}^{23} } \\ \\ \\ \\ \: \: \: \: \: \: \: = 1.379 \times {10}^{ - 11} \: \: \: \: moles[/tex]

Hope this helps you

True or False: When it is spring in the Northern Hemisphere, it is autumn in the Southern Hemisphere.

Answers

Answer:

That is true

Explanation:

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