Which of the following is a radioactive element?Sodium, Fluorine,Oxygen
francium

Answers

Answer 1

Answer:

Fluorine

Explanation:

These particles stick in the atoms and make them radioactive.


Related Questions

1.7 x 10 cm= significant figures

Answers

Answer:

its 2

Explanation:

(5) Use scientific notation, make the following conversions:
6.20 km to m​

Answers

Answer:

6200 meters

Explanation:

To convert from km to m you have to multiply the number by a thousand

Answer:

6.2×10^3 m

Explanation:

6.20×1000=6200m

In scientific notation 6200 = 6.2×10^3

A 2.26 M solution of KOH is prepared. Calculate the moles and mass of solute present in a 15.2-mL sample of this solution. The molar mass of KOH is 56.11 g/mol.

Answers

Answer:

0.0344 moles and 1.93g.

Explanation:

Molarity is defined as the ratio between moles of a solute (In this case, KOH), and the volume. With molarity and volume we can solve the moles of solute. With moles of solute we can find mass of the solute as follows:

Moles KOH:

15.2mL = 0.0152L * (2.26mol / L) = 0.0344moles

Mass KOH:

0.0344 moles * (56.11g/mol) = 1.93g of KOH

The order is Solumedrol 3 mg/kg for a child weighing 20 kg. Solumedrol is available as 125 mg/2ml. How many ml will be given

Answers

Answer:

0.96mL must be given

Explanation:

First, we need to obtain the mass of Solumedrol required for the child by using its mass. Then, with this mass we can solve the volume that must be administered:

Mass of solumedrol required:

20kg * (3mg / kg) = 60mg of solumedrol are required.

Volume given:

60mg Solumedrol * (2mL / 125mg) =

0.96mL must be given

which element can form an oxide with the general formula m2o or mo where m is a metal

Answers

Answer:

Because the compound has a formula of M2O, the number of valence electrons of M should be 1. Therefore, (1) Group 1 is the correct answer because elements in group 1 have 1 valence electron.

Explanation:

Will give brainliest

Answers

it shows the atomic number

What carpet Burns in a deficiency of O2 a mixture of CO and CO2 forms.Carbon Burns in excess O2 to form only CO2 and CO Burns in excess O2 to form only CO2. Calculate ΔH for C(graphite +1/2O2) →CO(g).

Answers

Answer:

Explanation:

From the combustion of carbon, the reactions occurring in limited oxygen conditions are:

[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]  

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]  

If it occurs in excess, then any leftover CO changes to CO2. i.e.

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]   ---- (1)

[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex]          ----- (2)

From (1), the enthalpy change is:

[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]

[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]

[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]

From (2), the enthalpy change is:

[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]

[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]

[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]

Subtracting (2) from (1), we get:

[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]

[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]

                                                                                                   

[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]

[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]

The enthalpy change ΔH of the reaction = -110.5 kJ/mol

How would a long period without sunlight affect the food web?

It would cause consumers to consume more food.

It would have no effect on the food web.

It would stop decomposers from breaking down matter.

It would stop producers from producing food.

Answers

Answer: it would stop producers from producing food.

Explanation: why? Without the action of the producers to turn sunlight into food, the producers would die, and consumers that rely on them would lose their food source and die too.

Answer:

It would stop producers from producing food

Explanation:

Producers would die, and if producers died, consumers would die too.

Hope this helps

Which is the weakest type of intramolecular force/bond?
a. Polar covalent b. Ionic c. Metallic d. Nonpolar covalent

Answers

Answer:

Non polar covlant

Explanation:

radiation is a measure of average kinetic energy of particles in an object true or false ​

Answers

Answer:false

Explanation:

How many milliliters of 60% carbonic acid must be mixed with how many milliliters of 15% carbonic acid to make 650 milliliters of a 38% carbonic acid solution

Answers

Answer:

348.9 mL of the 60% solution and 251.1 mL of the 15% solution.

Explanation:

First, we calculate how many mililiters of pure carbonic acid are there in 650 mL of a 38% solution:

650 mL * 38/100 = 247 mL

Then we can express the sum of both initial solutions as:

1)  x * 60/100 + y * 15/100 = 247

for the volume of carbonic acid; and

2)  x + y = 600 mL

For the volume of the solutions.

We now have a system of two equations and two unknowns (x is the volume of the 60% solution and y is the volume of the 15% solution).

We express x in terms of y in equation 2):

x = 600 - y

And replace x in equation 1):

(600 - y) * 60/100 + y * 15/100 = 247360 - 0.6y + 0.15y = 247-0.45y = -113y = 251. 1 mL

Finally we calculate x using equation 2):

x + 251.1 = 600x = 348.9 mL

A patient is prescribed 100mg/day of antibiotic for 2 weeks. The antibiotic is available in vials that contain 20mg/vial of the drug. How many vials are necessary for the entire treatment?

Answers

i have no idea, but i’m pretty sure you gotta divide

Give an example of chemical reaction that occurs in everyday life

Answers

Answer: metal and salt water

Explanation: salt starts to brake down metal and metal is everywhere in the ocean hope this helps

Answer:

baking a cake.

Explanation:

baking a cake is an example of a chemical reaction that happens daily because a new substance is forming when the cake is being baked. hope this helps! :)

A 275 g sample of a metal requires 10.75 kJ to change its temperature from 21.2 oC to its melting temperature, 327.5 oC. What is the specific heat of this metal

Answers

Answer:

[tex]c=0.127\ J/g^{\circ} C[/tex]

Explanation:

Given that,

Mass of the sample, m = 275 g

It required 10.75 kJ of heat to change its temperature from 21.2 °C to its melting temperature, 327.5 °C.

We need to find the specific heat of the metal. The heat required by a metal sample is given by :

[tex]Q=mc\Delta T[/tex]

c is specific heat of the metal

[tex]c=\dfrac{Q}{m\Delta T}\\\\c=\dfrac{10.75\times 10^3\ J}{275\times (327.5 -21.2)}\\\\=0.127\ J/g^{\circ} C[/tex]

So, the specific heat of metal is [tex]0.127\ J/g^{\circ} C[/tex].

Which two statements are true about all generators?
They convert motion energy to electric energy.
They have a fixed pair of magnets and a rotating metal coil.
They’re powered by fossil fuels.
They convert electric energy to motion energy.
They use the relative motion of a magnet and a coil of wire.

Answers

Answer:

they have a fixed pair of magnets and a rolling coil they convert motion into electric energy they are powered by fosile fuels they use reletive motion of a magnet and coil of a wire

Explanation:

Answer:

They convert motion energy to electric energy.

They use the relative motion of a magnet and a coil of wire.

Explanation:

This is the correct answer.

9. Which of these is not a mixture? *
Solution
Alloy
Amalgam
They are all mixtures.

Answers

Answer:

They are all mixture

Explanation:

last option

CHEMISTRY HELP
Once the following equation is balanced, what is the correct coefficient for Z₂?

Answers

Answer:

The coefficient of Z₂ is 1.

Explanation:

From the question given above:

X + ZY —> XY + Z₂

Next, we shall balance the equation to obtain the coefficient of Z₂. This can be obtained as follow:

X + ZY —> XY + Z₂

There is 1 atom of Z on the left side and 2 atoms on the right side. It can be balance by putting 2 in front of ZY as shown below:

X + 2ZY —> XY + Z₂

There are 2 atoms of Y on the left side and 1 atom on the right side. It can be balance by putting 2 in front of XY as shown below:

X + 2ZY —> 2XY + Z₂

Now, we have 1 atom of X on the left side and 2 atoms on the right side. It can be balance by putting 2 in front of X as shown below:

2X + 2ZY —> 2XY + Z₂

Now the equation is balanced.

Thus, the coefficient of Z₂ is 1.

Identify the type of solid from the description. Select from the following choices: metallic solid, network solid, molecular solid, ionic solid, or amorphous solid

Answers

Identify the type of solid from the description. Select from the following choices: metallic solid, network solid, molecular solid, ionic solid, or amorphous solid. a. This solid is ductile and conducts electricity.b. This solid is not conductive and has a low melting point.

Answer:

See explanation

Explanation:

A is a Metallic Solid

Let us look again at the physical properties of metals;

Metals are

DuctileMalleableSonorousHigh melting pointConducts electricity

We can now see that both ductility and electrical conductivity are metallic properties.

B is a Molecular solid

Molecules are formed when atoms share electrons. In molecules, there are no free electrons hence molecules do not conduct electricity.

Secondly, molecules are held together in the solid state by weak dispersion forces hence molecular solids have a low melting point.

What Is an example of weather?
A. The average rainfall in Arizona over the pervious three months
B. The increase in temperature over North America over the past decade
C. The time for high tide in Daytona Beach today
D. The temperature and wind speed in Philadelphia today

Answers

The answer is c the time for the high tide in Daytona beach today and because I guessed

(1) Phosphorus silicon is a semi-conductor

Answers

When Silicone is altered with Phosphorus, 4 of its electrons form covalent bonding and the 5th electron becomes delocalized and thus it increases electrical conduction

Answer:

blue blah blue blah

Explanation:

What is a molecule contains the genetic instructions for the development and functioning of all living organisms found in the nucleus of a cell

Answers

DNA (short for deoxyribonucleic acid)

What are 3 characteristics of all invertebrates

Answers

Answer:

None have backbones

No cell walls

Multicellular

Includes radial or bilateral body symmetry.

Explanation:

Which word describes the amount of matter an object contains?
altitude
density
mass
pressure

Answers

Mass witch would be c i covered this in class

Answer:

Mass

Explanation:

Answered this question multiple times and got it correct

Hope this helped!

Stay safe!

An isotope has three forms. 30% have a mass of 4 amu, 20% have a mass of 5 amu and
50% have a mass of 3 amu, Average atomic mass will be closest to

Answers

The average atomic mass will be 3.70 amu

We have to obtain the average atomic mass by multiplying the mass of each isotope in amu by the relative abundance of the given isotope as contained in the data of the question.

Hence;

Average atomic mass;

(0.30 * 4) + (0.20 * 5) + (0.50 * 3)

= 1.20 + 1.00 + 1.50

= 3.70 amu

https://brainly.com/question/13292428

How do sound waves travel? PLEASE HELP IF YOU WANT BRAINLEIST AND ME TO LIKE URE COMMENT!!
A. Sound causes the air near it to vibrate inwards.

B. waves radiate outward from a central point.

C. Sound moves randomly in different directions.

D. Sound transforms waves into different frequencies.

Answers

The answer is A. The vibration caused by the waves through the air eventually weaken, which is why sound diminishes easily over distance.

What is the molecular formula for a compound with a molar mass of 42.08g/mol and an empirical formula of ch2

Answers

Answer:

[tex]C_3H_6[/tex]

Explanation:

Hello!

In this case, since the empirical formula is the smallest representation of the molecular formula, it is known that the times in which the empirical formula is into the molecular formula is a whole number and is computed by dividing the molar mass of the molecular formula by that of the empirical formula as shown below:

[tex]\frac{42.08g/mol}{12.01+1.01x2}= \frac{42.08g/mol}{14.03g/mol}=3[/tex]

Thus, the molecular formula times the empirical formula by 3 to obtain:

[tex]C_3H_6[/tex]

Regards!

Give the IUPAC name for each compound.

Answers

Answer:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

Explanation:

Hello!

In this case, according to the IUPAC rules for the listed alkyl halides, we first need to name the halogens (considering periodic order) then alkyl radicals and finally the parent chain; thus, the names are given below:

a. 1-fluoro-3,3,4-trimethyl-pentane.

b. 1-iodo-3-ethyl-2-methyl-hexane.

c. 1,3-dichloro-5-dimethyl-hexane.

d. 1-bromo-3-methyl-cyclopentane.

e. 5-chloro-1-bromo-1,1,5-trimethyl-pentane (radicals are not clear).

Best regards!

how are the terms atom and element different?

Answers

Answer:

Element is made from same type of atoms

While atom is present in element made up of different particles like proton neutrons electron etc

Explanation:

A particular atom will have the same number of protons and electrons and most atoms have at least as many neutrons as protons. An element is a substance that is made entirely from one type of atom. For example, the element hydrogen is made from atoms containing just one proton and one electron.

What is the wavelength of light emitted when the electron in a hydrogen atom undergoes transition from an energy level with n = 4 to an energy level with n = 2?

Answers

Answer:

[tex]4.86\times10^{-7}\ \text{m}[/tex]

Explanation:

R = Rydberg constant = [tex]1.09677583\times 10^7\ \text{m}^{-1}[/tex]

[tex]n_1[/tex] = Principal quantum number of an energy level = 2

[tex]n_2[/tex] = Principal quantum number of an energy level for the atomic electron transition = 4

Wavelength is given by the Rydberg formula

[tex]\lambda^{-1}=R\left(\dfrac{1}{n_1^2}-\dfrac{1}{n_2^2}\right)\\\Rightarrow \lambda^{-1}=1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\\\Rightarrow \lambda=\left(1.09677583\times 10^7\left(\dfrac{1}{2^2}-\dfrac{1}{4^2}\right)\right)^{-1}\\\Rightarrow \lambda=4.86\times10^{-7}\ \text{m}[/tex]

The wavelength of the light emitted is [tex]4.86\times10^{-7}\ \text{m}[/tex].

How are food webs and food chains related? HELP IF YOU WANT BRAINLEIST!!

Food webs only contain consumers.

Food webs consist of only one food chain.

Food webs are made of many food chains.

Food webs only contain producers.

Answers

Answer: Food webs are made of many food chains is the answer.

Explanation:

Food web consists many food chains.

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