answer number 12 for me

Answer:

los metales alcalinotérreos: berilio (Be), magnesio (Mg), calcio (Ca), estroncio (Sr), bario (Ba) y radio (Ra).

o simplemente llamado grupo 2A

Explanation:

it is held every 4-5 years

Explanation:

4.5×6.022×10²³

27.099×10²³

According to Avogadro's number, there are 27.10×10²³ atoms in  4.5 moles of Al.

Avogadro's number is defined as a proportionality factor which relates number of constituent particles with the amount of substance which is present in the sample.

It has a SI unit of reciprocal mole whose numeric value is expressed in reciprocal mole which is a dimensionless number and is called as Avogadro's constant.It relates the volume of a substance with it's average volume occupied by one of it's particles .

According to the definitions, Avogadro's number depend on determined value of mass of one atom of those elements.It bridges the gap between macroscopic and microscopic world by relating amount of substance with number of particles.

Number of atoms can be calculated using Avogadro's number as follows: mass/molar mass×Avogadro's number.As 1 mole =6.023×10²³ atoms , thus,4.5 moles =4.5×6.023×10²³ = 27.10×10²³  atoms.

Thus, there are 27.10×10²³ atoms in  4.5 moles of Al.

Learn more about Avogadro's number,here:

https://brainly.com/question/11907018

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Answer:

The period number on the Periodic table tells you the total number of orbits that the atom will have. In other words, the period number indicates the number of energy levels (or energy orbit) of an atom. For example, 1st period indicates that these elements possess 1 energy shell (or energy orbit).

Explanation:

Answer:

When the ambulance is coming towardss you the waves are smushed together and sound higher pitched but then it passes you and when tracveling away the waves are scretched out so the whee whoo sounds lower and that is because of the doppler effect

Answer:

C)12.09 Ampere

Explanation:

V= IR

Where I= current of the system

R= resistance= 0.67 ohm

V= potential difference=8.1 volts

Substitute the values

8.1= I× 0.67

I= 8.1/0.67

=12.09 Ampere

17 × ( 2 × 16 ) = 17 × 32 = 544 grams

___________________________

Answer: 4.48 or 4.47

Answer: (A) a cobalt atom contains 27 protons, and most cobalt atoms contain 32 neutrons.

Explanation: just answered the question and that was the correct answer

Answer:     The answer is :     A cobalt atom contains 27 protons and MOST  neutral cobalt atoms contain 32 electrons

Explanation:   I took the test

Answer: i need help

Explanation:

Answer:

A climate change

Explanation:

the surrounding area would be effected in all ways imaginable, such as change in air, soil, water, plants, animals. and if you eat those said animals those harmful things can transfur into you

Answer:

48 °C

Explanation:

q = 90J

m = 15 g

C = 0.126 J/gºC

q = mct

90 = (15)(0.126)t

t = 47.62 °C = 48 °C

Answer:

Explanation:

Formula

E = m * c * Δt

Δt is what you seek.

Givens

E = 90 joules

m = 15 grams

c   = 0.126

Solution

90 = 15 * 0.126 * Δt         Divide by 15

90/15 = 15/15 * 0.126 * Δt

6 = 0.126 * Δt                  Divide by 0.126

6/0.126 = Δt

47.619 = Δt

Δt = 48 oC

Answer:

0.113 liters

Explanation:

5.41 M / 47.71 moles = 0.113 liters

Answer:

(ii) 1 dye

(iii) Food coloring F is insoluble in the solvent

(iv) 'E' and 'H'

(b) Food colouring G

Explanation:

Paper chromatography principle is based on the rates of migration of chemicals across a sheet of paper which are different and it consists of a stationary phase such as the water in the paper and a mobile phase such as the solvent resulting in the partitioning of the components of the mixture across the paper

The solution components are positioned to start in one place from where they migrate and separate out on the chromatography paper

(ii) The number of components into which the food colouring 'H' separates into = 1

Therefore, the number of dyes in food colouring 'H' = 1 dye

(iii) Food coloring 'F' does not move because it is insoluble in the solvent, which is the mobile phase

(iv) The food colouring that contains the dye that is likely to be most soluble in the solvent are does for which the dyes travel furthest, which are;

Food coloring 'E' and 'H'

(b) Using a similar question solution found on 'tutor my self' website, we have;

The [tex]R_f[/tex] values are given as follows;

[tex]R_f = \dfrac{Distance \ moved \ by \ dye}{Distance \ moved \ by \ solvent}[/tex]

The distance moved by the solvent = 5 units

The distance moved by dyes in food colouring 'E' and 'H' = 4 units

The distance moved by dye in food colouring 'G' = 3.3 units

The distance moved by the second dye in food colouring 'E' = 2.7 units

By inspection, we get;

[tex]R_f[/tex] dye in food colouring 'G' = 3.3/5 = 0.66,

Therefore, the dye with [tex]R_f[/tex] value closest to 0.67 is the dye in food colouring 'G'.

Answer:

600 mL

Explanation:

molarity 1 * volume 1 = molarity 2 * volume 2. So this means 12 * 250 = 3000 and divide that by 5 to get 600 mL.

Answer:

Deci trebuie sa te aplici cu 2 din3 pe suprafata pamanyului chinez

Explanation:

Deci 1287+2086+2762+7:5

Answer:

it's A.

Explanation:

have uh good day ma :)))))))

Answer:

338.38 K

Explanation:

Applying,

PV = nRT............... Equation 1

Where P = pressure, V = Volume, R = Temperature, n = number of moles, T = temperature.

Make T the subject of the equation,

T = PV/nR............. Equation 2

From the question,

Given: P = 1.95 atm, V = 12.3 L, n = 0.854 moles

Constant: R = 0.083 L.atm/K.mol

Substitute these values into equation 2

T = (1.95×12.3)/(0.854×0.083)

T = 338.38 K

Answer:

Alkynes are saturated hydrocarbons

Explanation:

Alkynes are groups of hydrocarbons that have the general formula of {Cn H2n - 2}. They have a triple carbon to carbon bond (C≡C) in their structure. Ethyne (HC≡CH) is the first member of the alkyne series.

Alkynes like alkenes are unsaturated hydrocarbons because of their triple and double carbon bonds respectively. Unsaturated hydrocarbons do not have a complete hydrogen atom in their structural composition. Hence, the statement that "Alkynes are saturated hydrocarbons" is FALSE.

Answer:

132.53 J/kg.°C

Explanation:

Applying,

Q = cm(t₂-t₁)................ Equation 1

Where Q = amount of heat, c = specific heat capacity of platinum metal, m = mass of platinum metal, t₁ = initial temperature, t₂ = Final temperature.

Make c the subeject of the equation

c = Q/m(t₂-t₁).............. Equation 2

From the question,

Given: Q = 5.7 J. m = 18.7 g = 0.0187 kg, t₁ = 21.2°C, t₂ = 23.5°C

Substitute these values into equation 2

c = 5.7/[0.0187×(23.5-21.2)]

c = 5.7/0.04301

c = 132.53 J/kg.°C

Answer: What is the mass of disulfur pentoxide (S2O5)?

Explanation:144.14g/mol

Answer:

they are all planets

Explanation:

Answer:

Because Sulphuric acid(H2SO4) is one of the substance which have a very high vigourous reaction if mix with chemicals thats why we take the same sulphuric acid but having lighter effects known to be as Dil.Sulphuric And so it is generally use for precaution while during experimentations Thats why we use it.

Hope it helps

Answer:

"500 Joule/sec" is the right answer.

Explanation:

The given values are:

Force,

F = 1000 N

Velocity,

s = 10 m

Time,

t = 20 s

Now,

The power will be:

=  [tex]\frac{Force\times Velocity}{Time}[/tex]

On putting the values, we get

=  [tex]\frac{1000\times 10}{20}[/tex]

=  [tex]\frac{10000}{20}[/tex]

=  [tex]500 \ Joule/sec[/tex]

Answer:

True

Explanation:

Fungi reproduce by spawning absurd amount of spores greatly increasing the survival rate of the fungi.

Answer:

true

Explanation: