HELpPPPPppp!!!!!! will mark brainless

Answer: 3

Explanation: 5 times a number would be 5x, then increase that by 4 is 5x+4.  The problem then says 5x + 4 ≥ 19.  If we solve for x then we get x ≥ 3 so x has to be greater than or equal to 3, so the smallest number it could be is 3.  You can even try any number smaller than 3 and see it doesn't work.  even something like 2.9

Answer:

Alkali metals

Explanation:

The lowest number of valence electrons is found in the alkali metals (group 1), which have only one valence electron per atom.

Answer:

Alkali metals:) im 100% sure because i just got done learning everything in the periodic table:)

Explanation:

D is the answer -3                            m              

Answer:

2

Explanation:

Answer:

1. Sperm - The male reproductive cell

2. Fertilization - The union of the male gamete (sperm cell) and the female gamete (egg cell)

3. Conception - The fertilization of a female egg cell with a male sperm cell

4. Testes, Testicles - Male gonads

5. Ovary, Ovaries - Female gonads

6. Gonad - Gamete-producing organ in animals

7. Eggs - Female reproductive cells

8. Hormone - a body chemical that controls growth and activity

Explanation:

Hope this helped!

Answer:

filtration is the answer

Explanation:

The formula of a compound is written based on the valency of each bonded atoms. The formulas  Mg₂(SO₄)₃, Rb₃As are incorrect. Such compounds does not exist.

The formula of a chemical compound is written based on the number of atoms participated in bonding.   Magnesium is second group element having two valence electrons.

Magnesium thus donates its two electrons into the bonding atom or group. The sulphate group SO₄ have a valency of 2 it gains two electrons from Mg when bonded.

Thus the formula of magnesium sulphate being MgSO₄ and not Mg₂(SO₄)₃. Similarly Rb is a second group metal having two valence electrons. Its valency being two. As is a halogen with valency one. Thus they cannot form a compound like Rb₃As.

Hence, option a and b are incorrect formulas.

To find more about chemical formulas, refer the link below:

https://brainly.com/question/11995171

#SPJ2

Answer:

4.26m

Explanation:

Molality , m, is an unit of concentration in chemistry defined as the ratio between moles of solute (In this case, NaCl) and kg of solvent (In this case, water).

To solve the question we need to find the moles of NaCl and the mass of water in kg:

Moles NaCl -Molar mass: 58.44g/mol-:

11.7g * (1mol / 58.44g) = 0.200 moles

Mass of Water in kg:

47g * (1kg / 1000g) = 0.047kg

Molality is:

0.200 moles / 0.047kg =

4.26m

Answer:

57 mL

Explanation:

To make things clear, when 769 mL of ethanol were mixed with 507 mL of water, the resulting volume was not (769+507) 1276 mL, but a lower value. This is because of the interactions between liquid molecules.

First we calculate how many grams of ethanol are there in 769 mL, using the given density:

Then we convert 606.97 g of ethanol into moles, using its molar mass:

Now we calculate the actual volume of the solution, using the definition of molarity:

Finally we convert 1.219 L to mL, and calculate the difference in volume:

Answer:

Option A an E.

Explanation:

Energy can be described as the capability to do work. It is what has to be transferred to an object in order to get this object to do work. Energy can be in various forms such as heat energy, kinetic, potential, electrical, chemical, nuclear etc.

It takes energy to do quite a number of things, from cooking food to driving and also in engaging in exercises.

Explanation:

Cada producto o servicio, independientemente de su propósito, debe ser seguro de usar y desarrollado de acuerdo con los más altos estándares de calidad y seguridad.

Algunos ejemplos de cálculo incorrecto de ingredientes que tendrían graves consecuencias químicas podrían ser:

Medicamentos y vacunas: Este es quizás uno de los ejemplos que tendría las consecuencias más graves para las personas si hubiera un cálculo incorrecto de ingredientes, ya que la producción de medicamentos y vacunas es una industria que requiere la máxima calidad agregada debido a que se ocupa directamente de la salud y los errores de formulación pueden agravar la enfermedad y causar la muerte. Actualmente tenemos el ejemplo de la vacuna para el control de la pandemia, que antes de ser aprobada tuvo que someterse a una serie de investigaciones, pruebas en humanos y diferentes fases para demostrar su efectividad y no causar daño al organismo humano.

Cosméticos: Existen cosméticos de la industria de la belleza que tienen la función de prevenir el envejecimiento cutáneo, alisar el cabello, etc. Por tanto, un cálculo incorrecto de los ingredientes químicos también podría provocar daños irreversibles a la salud, como quemaduras en la piel, caída del cabello, alergias, cáncer, etc.

Alimentos: La industria alimentaria utiliza componentes químicos con el fin de conservar los productos y aumentar la vida útil, por lo que si se usan en cantidades mayores de las necesarias, dichos compuestos pueden causar enfermedades en las personas como intoxicación alimentaria, cáncer, gastritis, etc.

Answer:

True

Explanation:

this is part of the cell theory

Answer:

A. 0.48mol O2

Explanation:

The balanced equation is given as follows:

2CH3OH + 3O2 → 2CO2 + 4H2O

This shows that 2moles of CH3OH is required to react with 3 moles of O2

If 0.32 moles of CH3OH are reacted, then;

0.32 × 3/2 moles of O2 is required

= 0.96/2

= 0.48mol of O2

Answer:

I will draw how the city looks like

Answer:

.5

Explanation:

Answer:

1.5

Explanation:

1.5

Answer:The answer is C) The total mass of C and D only.

Answer:

The mass of water produced is 4.29 g.

Explanation:

Given;

reacting mass of ethane, C₂H₆ = 2.5 g

reacting mass of oxygen, O₂ = 5.0 g

The balanced combustion reaction is given as follows;

2C₂H₆   +   7O₂ ---------------->  4CO₂    +   6H₂O

Based on the balanced equation above;

                                     requires

7.0 moles of oxygen ----------------------->   2.0 moles of ethane

                                   requires

5.0 g of oxygen      -------------------------->  x gram of ethane

x = (2 x 5) / 7

x = 1.43 g

Ethane is in excess of 1.07g (2.5 g - 1.43g)

Now, determine the mass of water produced by 1.43 g of ethane;

                                   requires

2.0 moles of ethane ----------------------->   6.0 moles of water

                                   requires

1.43 g of ethane      -------------------------->  y  gram of water

y = (6 x 1.43) / 2

y = 4.29 g

Therefore, the mass of water produced is 4.29 g.

Answer: 300 g

Explanation: I guessed and got it right

420 liter of volume is occupied by 300 grams of methane gas at standard temperature and pressure (STP).

Ideal gas equation of methane gas at STP (standard temperature pressure) can be written as:

PV = nRT, where

P = pressure = 1 atm

V = volume = 420 L (given)

R = universal gas constant = 0.082 L.atm / k.mole

T = absolute temperature = 273 K

n = no. of moles to find?

Putting all these values in the above equation and calculated for the n:

n = (1 × 420) / (0.082 × 273) = 18.76 moles

Now we calculate mass of methane by the definition of moles as:

n = W/M, where

M = molar mass of methane = 16 g/mole

W = to find?

W = 18.76 × 16 = 300.2 grams or 300grams.

Hence, option (c) is correct i.e. 300 grams of methane occupy 420 L volume.

To know more about ideal gas equation, visit the below link:

https://brainly.com/question/12873752

Answer:

104 g

Explanation:

i just solved it

Answer:

2 electron shells

hope it helps

and your day will be full of happiness

Answer:

B.mass of the neutrons and protons

Explanation:

hope it's help..

Answer:

finally found

31th July 2000

Answer:

an agent that helps accept electrons on others like oxygen, halogens

Explanation:

a substance that tends to bring about oxidation by being reduced and gaining electrons.

Please mark me as brainliest

Answer:

Distance also affects the apparent brightness of an object. A distant, but very energetic star can appear dimmer to us than a lower-energy, but closer one. ... Each of their effective temperatures results in a different brightness for the object. The quasar, however, is very far away, and so appears dim.

Explanation:

The amount of chlorine will be 0.791 gram required to completely react with 0.0223 moles of sodium iodide .

The given chemical reaction is :

2Nal + [tex]Cl_{2}[/tex] → 2NaCl + [tex]I_{2}[/tex]

It is given that:

Amount of sodium iodide = 0.0223 mol.

Atomic mass of chlorine = 35.45 g.

The amount of chlorine can be calculated as:

0.0223mol. NaI × (1mol. Cl₂/2mol. NaI) × (35.45g/1mol. Cl2)

=0.791 grams

Therefore, the correct answer will be option (D).

To know more about sodium chloride.

https://brainly.com/question/20273068

#SPJ1

Answer:

I took a screen shot of your image, and wrote on top of it!

Explanation:

Hope this helps! :)

Answer:

1. false

2. true

Explanation:

I hope this helps

Answer:

52.5 g

Explanation:

Density= mass/volume

Rearranging the equation gives us m= d(V)

m= d(V)

m= (10.5 grams/cm^3)(5 cm^3)

m= 52.5 g