The radioisotope radon-222 has a half-life of 3.8 days. How much of a 73.9-g sample of radon- (3 222 would be left after approximately 23 days?​

Answer:

The Eurasian plate(another major plate), the Aegean sea plate and the Anatolian plate share the north border. The Antarctic plate that contributes to the south of the African plate, is also a major plate.

Answer:

B. Prepare solutions of different acid concentrations, measure 50 milliliters of each into different beakers, and place metal samples of different types but of the same mass into the beakers.

Explanation:

Since Michael is studying the factors that affect corrosion of metals, and wants to test the effect that different concentrations of an acid will have on the corrosion of a metal, using different acid concentrations of the same volume on different metal samples of the same size would give a much better than all the other options because, a standard volume of acid is used and also a standard mass of metal is used. So, the effect can be measured quantitatively since we have the same quantity of sample.

So, option B is the answer

Answer: The correct net ionic equation for the reaction is [tex]2H^{+}(aq)+2OH^{-}(aq)\rightarrow 2H_2O(l)[/tex]

Explanation:

Net ionic equation is defined as the equations in which spectator ions are not included.

Spectator ions are the ones that are present equally on the reactant and product sides. They do not participate in the reaction.  

The balanced molecular equation is:

[tex]Ca(OH)_2(aq)+H_2SO_4(aq)\rightarrow CaSO_4(aq)+2H_2O(l)[/tex]

The complete ionic equation follows:

[tex]Ca^{2+}(aq)+2OH^-(aq)+2H^+(aq)+SO_4^{2-}(aq)\rightarrow 2Ca^{2+}(aq)+SO_4^{2-}(aq)+H_2O(l)[/tex]

As calcium and sulfate ions are present on both sides of the reaction. Thus, they are considered spectator ions.

The net ionic equation follows:

[tex]2H^{+}(aq)+2OH^{-}(aq)\rightarrow 2H_2O(l)[/tex]

Hence, the correct net ionic equation for the reaction is [tex]2H^{+}(aq)+2OH^{-}(aq)\rightarrow 2H_2O(l)[/tex]

Answer:

B. no reaction     

Explanation:

Answer:

28.16 g/mol

Explanation:

From Graham's law;

Let the rate of diffusion of gas X be 1.25

Let the rate of diffusion of CO2 be 1

Molecular mass of gas X= M

Molecular mass of CO2 = 44g/mol

1.25/1=√44/M

(1.25/1)^2 = 44/M

1.5625 = 44/M

M= 44/1.5625

M= 28.16 g/mol

Answer:

c i took the text

Explanation:

Answer:

2Li + ZnBr2 ->2LiBr + Zn

3Ca + Al2O3 ->2Al + 3CaO

Explanation:

Spontaneous reactions are reactions that can happen on their own. For a spontaneous reaction to occur, a metal that is higher in the activity series must displace a metal that is lower in the activity series from its solution and not vice versa.

If we look at the two reactions selected in the answer, lithium is above zinc in the activity series and calcium is above aluminum in the activity series hence the two reactions occur spontaneously.

Answer:

Approximately 10.5g or 10.4g [tex]SrF_{2}[/tex]

Answer: Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.

Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.

Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.The reaction for decomposition of water into oxygen and hydrogen is as follows:

Electrolysis is passing an electric current through a liquid containing ions so that decomposition reaction takes place.When an electric current is passed through acidified water, it decomposes to give hydrogen and oxygen gas. The hydrogen gas is obtained at the cathode and the oxygen gas is obtained at the anode.The reaction for decomposition of water into oxygen and hydrogen is as follows:2H2O(l) -------> 2H2(g) + O2(g)

Answer:

1100L.

Explanation:

Answer: The correct answer is heat will flow from the boiling water into the frozen metal.

Explanation:

According to the law of conservation of energy, energy cannot be destroyed nor created but it can be transformed from 1 form to another form.

There are 3 processes of heat transfer:

The heat moves from a hot surface to a cold surface to maintain equilibrium.

We are given:

A metal is placed in a freezer (cold object) and another metal is placed in an oven (hot object) and then both the metals are placed in boiling water.

Initially, the heat will flow from the boiling water (hot object) into the frozen metal (cold object) to maintain equilibrium

Hence, the correct answer is heat will flow from the boiling water into the frozen metal.

Answer:

C

[tex] \triangle \: H {}^{ \theta} _{s} = lattice \: energy + hydration \: energy \\ = + 2526 + ( - 2003 + (2 \times - 340)) \\ + 2526 - 2683 \\ = - 157 \: kjmol {}^{ - 1} [/tex]

Answer:

Is there a picture for it

Explanation:

because it would be a hard

Answer:

Enthalpy is the amount of heat released or absorb. The total enthalpy can be found by subtracting the products' enthalpy by the reactants' enthalpy

Explanation:

just use the molar ratios to figure it out. Notice, you have to balance the chemical equation.

Answer:

YES!!!

Explanation:

Strong acids and strong bases are both strong electrolytes. In contrast, only a fraction of the molecules of weak acids and weak bases react with water to produce ions, so weak acids and weak bases are also weak electrolytes.

ahí esta la respuesta espero que te sirva

Answer:

alloy,copper,gold, silver,cobalt

Explanation:

Answer: The balanced nuclear equation for the alpha decay of Sr-90 is [tex]_{38}^{90}\textrm{Sr}\rightarrow _{36}^{86}\textrm{Kr}+_2^4\alpha[/tex]

Explanation:

A nuclear reaction is defined as the reaction in which the changes in the nucleus of an atom take place and usually form a different element. The types of decay processes are:

Alpha decay is the process in which a heavy nucleus decays into a light nucleus with the release of an alpha particle. This alpha particle carries a charge of +2 units and has a mass of 4 units. It is also known as the helium nucleus. The general equation for this decay process is:

[tex]X_Z^A\rightarrow Y_{Z-2}^{A-4}+\alpha _2^4[/tex]

The nuclear equation for the alpha decay of strontium-90 isotope follows:

[tex]_{38}^{90}\textrm{Sr}\rightarrow _{36}^{86}\textrm{Kr}+_2^4\alpha[/tex]

Answer:

A

Explanation:

Alkanes undergo substitution reaction with halogen molecules in the presence of light. This reaction occurs by free radical mechanism and the initiation step is the formation of the halogen radical.

The propagation steps involves the abstraction of a hydrogen from the alkane by the halogen radicals.

The termination steps involves the coupling of alky radicals.

Thus for the reaction of ethane and chlorine;

C2H6 + Cl2 -------> C2H5Cl + HCl

Answer:

HFusion*mass + Spec.Heat*mass*ΔT + HVap*mass

80cal/g*50.0g + 1.00cal/g°C*50.0g*(100°C-0°C) + 540cal/g*50g

3.60x10⁵cal

Explanation:

Using the HFusion we can find the heat needed to convert the ice to liquid water.

With specific heat capacity we can find the heat needed to increase the temperature of water from 0 to 100°C.

With HVap we can find the heat to convert the liquid water into steam.

The equations are:

Computing the values:

36000cal =

water is to gas as liquid is to solid

Answer:

d sguro

Explanation:

I'm not sure kung ayan ba

Answer:

The value of N would be 4.

Explanation:

The equation would be 2n^x = 32 and therefore, 4.

Answer:

the answer is salt because it has a uniform and definite composition

Explanation:

Your image is saying "Can't load image on this device."