eek helpppp ill give brainliestt

Answer:

120 gram sample of a radioactive element, how many grams of that element will be left after 3 half-lives have passed? If you have a 300

Explanation:

Hope this helps!

Answer:

The carrying capacity of this population would be 125 we know this because we see that this number occur multiple times and seems to be the tipping point after which the number of the population always go down

Answer:

The carrying capacity of this population would be 125 we know this because we see that this number occur multiple times and seems to be the tipping point after which the number of the population always go down

Explanation:

Answer:

Explanation:

di) number of protons is 12 for all, number of neutrons is 13 for mg- 25 and 14 for mg-26

Answer:

Is used to predict the spectra of hydrogen and hydrogen like species

Explanation:

The Bohr's model of the atom was propounded by Neis Bohr. In his theory, an atom is composed of quantized energy levels in which electrons may be found.

The transition of an electron between energy levels leads to the absorption or emission of energy in the form of a photon of visible light. The energy absorbed or emitted depends on the energy difference between the two energy levels.

The model is successful at predicting the electronic spectra of one electron species but totally fails when the specie has more than one electron. Also, the model fails to show the true shape of the electron orbitals within an atom.

The general chemical equation for the complete combustion (or burning) of some hydrocarbon fuel is, in words, as follows:

hydrocarbon fuel and oxygen gas react to produce carbon dioxide gas and water vapor,

or, using chemical notation,

[tex]\mathrm{C_xH_y} + z\mathrm{O_2} \rightarrow \mathit{x}\mathrm{CO_2} + \frac{\mathit{y}}{2}\mathrm{H_2O}[/tex]

where

[tex]z = x + \frac{y}{4}.[/tex]

Don't worry if that looks daunting. In our case, we are given the identity of the fuel (methane, or CH₄), so our equations will be straightforward.

In words: Methane gas and oxygen gas react to produce carbon dioxide gas and water vapor (or methane gas + oxygen gas → carbon dioxide gas and water vapor).

In chemical notation:

[tex]\mathrm{CH_4}_{\text{(g)}} + 2\mathrm{O_2}_{\text{(g)}} \rightarrow \mathrm{CO_2}_{\text{(g)}} + 2\mathrm{H_2O}_{\text{(g)}}.[/tex]

Answer:

a. 47 electrons

b. 6 electrons

c. 11 electrons

d. 10 electrons

e. 53 electrons

Explanation: If you are talking about neutral atoms (where as the number of protons in an atom is equal to the number of electrons in the atom), or are just being introduced to atoms then the number of electrons will be equal to the number of protons the atom has. Or vice versa, the number of protons will be equal to the number of protons in an atom. For example, in a neutral atom, with 51 protons, will have 51 electrons. Or an atom with 5 electrons will have 5 protons.

Answer:

24.7 C

Explanation:

I don't know how

The final temperature of 1000 ml water by the addition of 5 g ammonium perchlorate has been 24.7 degree Celsius.

With the addition of 5 g of ammonium perchlorate, the drop in temperature has been:

The addition of 5 g sample to 100 ml water has absorption of energy, that results in change in temperature of 3 degree Celsius.

The heat absorbed by sample has been given as:

Heat = mass × specific heat × change in temperature

Since, the same mass of sample has been added to 25 degree Celsius water, according to law of conservation, the change in density for both the changes has been equivalent.

The ratio of masses has been equivalent to the ratio of volume.

[tex]\rm \dfrac{Mass\;at\;1000\;ml}{Mass\;at\;100\;ml}\;=\;\dfrac{Volume\;at\;1000\;ml}{Volume\;at\;100\;ml}\\\\\\\dfrac{Mass\;at\;1000\;ml}{Mass\;at\;100\;ml}\;=\;\dfrac{1000\,ml}{100\;ml}\\\\\\\dfrac{Mass\;at\;1000\;ml}{Mass\;at\;100\;ml}\;=\;10[/tex]

Since, the mass at 100 ml and mass at 1000 ml has been equal, the heat absorbed by the sample has also been equal. Equating the values:

Mass at 100 ml × Specific heat × Change in temperature = Mass at 1000 ml × Specific heat × Change in temperature

[tex]\rm 3\;degree\;Celsius\;= \;\dfrac{Mass\;at\;1000\;ml}{Mass\;at\;100\;ml}\;\times\;Change\;in\;temperature\\\\3\;degree\;Celsius\;= \;10\;\times\;Change\;in\;temperature\\\\Change\;in\;temperature\;=\;\dfrac{3}{10}[/tex]

Change in temperature =  0.3 degree Celsius.

The initial temperature of water has been 25 degree Celsius. The change in temperature has been given by:

Change in temperature = Initial temperature - Final temperature

0.3 degree Celsius = 25 degree Celsius - Final temperature

Final temperature = 25 - 03 degree Celsius

Final temperature = 24.7 degree Celsius.

The final temperature of 1000 ml water by the addition of 5 g ammonium perchlorate has been 24.7 degree Celsius.

For more information about the final temperature, refer to the link:

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Answer:

it is option A hope it helps

The properties of nonmetallic oxides include acidity and covalent character. Hence, option A is correct.

Non - metals are elements in the rightmost side of the periodic table. Non -metals are mostly gases and some of them include, metalloids also. Non-metals are commonly electron -deficient and some of them are highly electronegative.

A compound shows covalent character, if the electrons are shared between the constituent atoms. Covalency increases from left to right in periodic table.

As the covalent character increases, acidity increases. Oxides of non-metals are electrophiles and acts as Lewis acids. They are all covalent compounds. Therefore, option A is correct.

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Answer:

B

Explanation:

Decreasing the sample size of the liquid

hope it helps!

Answer:

The boiling point

Explanation:

The boiling point is the temperature where a liquid starts to boil.

Answer:

the boiling point.

Explanation:

Answer: The number of protons in cation is more than the number of electrons

Explanation:

cations are positive ions that means that they lose electrons to be stable nd have electron configuration (atomic number ) equivalent to the preceding noble gas

as : sodium 11 , it loses on electron to be stable and its electron configuration is equivalent to neon 10

so ,the number of protons in cation is more than the number of electrons

i hope it helps!

Answer:

ammonia being lighter than air, is collected by downward displacement of air in an inverted gasjar

The gas jar is used to collect ammonia gas. This gas can be barely dissolved in water. As a result, the downward displacement of water does not gather it in the jar.

With the formula NH3, ammonia is a nitrogen and hydrogen inorganic chemical. Ammonia, the simplest pnictogen hydride and a stable binary hydride, is a colorless gas with a strong, pungent odor.

Because it is simpler to install inlets and outlets in one end of an erect gas jar than it is to install them on the side or the bottom, which are required for placement on a stable surface.

Ammonia is prepared in a laboratory by forcing air downward to collect the gas. Due to the high solubility of ammonia in water, it is impossible to collect ammonia gas over water.

Thus, The gas jar is used to collect ammonia gas.

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Answer:

mechanical digestion is the physical part of digestion

Answer:

mechanical digestion

Explanation:

a. 0.137

b. 0.0274

c. 1.5892 g

d. 0.1781

e. 5.6992 g

Given

Reaction

2 C4H10 + 13O2 -------> 8CO2 + 10H2O

2.46 g of water

Required

moles and mass

Solution

a. moles of water :

2.46 g : 18 g/mol = 0.137

b. moles of butane :

= 2/10 x mol water

= 2/10 x 0.137

= 0.0274

c. mass of butane :

= 0.0274 x 58 g/mol

= 1.5892 g

d. moles of oxygen :

= 13/2 x mol butane

= 13/2 x 0.0274

= 0.1781

e. mass of oxygen :

= 0.1781 x 32 g/mol

= 5.6992 g

0.137moles of water is formed, 0.0274 moles or 1.5892 g of butane burned and 0.1781 moles or 5.6992 g of O₂ is used.

Those reaction in which fuel is oxidized by the oxygen molecules and produce carbon dioxide and water molecule.

Given chemical reaction is:
2C₄H₁₀ + 13O₂ → 8CO₂ + 10H₂O

Given mass of water = 2.46 grams

Moles will be calculated as:

n = W/M, where

W = given mass

M = molar mass

(a) Moles of water formed is calculated as:

Moles of water n = 2.46g / 18 g/mol = 0.137moles

(b) From the stoichiometry of the reaction, it is clear that:

10 moles of water = produced by 2 moles of butane

0.137 moles of water = produced by 2/10×0.137=0.0274 moles of butane

(c) Weight of butane is calculated by using moles:

W = 0.0274 × 58 g/mol = 1.5892 g

(d) From the stoichiometry of the reaction, it is clear that:

2 moles of butane = react with 13 moles of O₂

0.027 moles of butane = react with 13/2×0.027=0.1781 moles of O₂

(e) Mass of oxygen is calculated as:
W = 0.1781 x 32 g/mol = 5.6992 g

Hence, (a) 0.137moles, (b) 0.0274 moles, (c) 1.5892 g, (d) 0.1781 moles and (e) 5.6992 g.

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Answer:

na+then mg2+ then al3+

Explanation:

this is due to the distance between their nucleus and valence electron

Answer:

The answer is intrusive igneous and extrusive igneous.

Explanation:

I’ve done the question on A P E X

Answer: transporting oxygen-rich blood to the body

Explanation:

Answer:

150g-125g

=25 of hot chocolate mix

Answer:

72.2 ml

Explanation:

The neutralization equation between HBr (acid) and NaOH (base) is the following:

HBr(aq) + NaOH(aq) → NaBr(aq) + H₂O(l)

We can see that 1 mol of HBr reacts with 1 mol of NaOH. At the equivalence point, the total number of moles of HBr reacts with the total number of moles of NaOH. The number of moles can be calculated as the product between the molarity (M, in mol/L) and the volume (V). So, we can equal the quantities of acid and base, as follows:

moles HBr = moles NaOH

M(HBr) x V(HBr) = M(NaOH) x V(NaOH)

Now, we calculate the volume of NaOH with the data:

V(NaOH)= M(HBr) x V(HBr)/M(NaOH)

              = (2.60 mol/L x 50.0 ml)/(1.80 mol/L)

              =72.2 ml

Actually, no. While their mass may be the same (1kg), the volume of lead is a lot smaller than that of feathers. As there is the same mass stuffed in a smaller space, it must be denser. The density of water is 1 g/cm3, so if the density of the lead is more than 1g/cm3, it has to sink

Answer:

If the solution is not in contact with air, nothing will happen. If the solution is in contact with air, it will be not a reaction between copper, water and sodium chloride..

in the end there will be no reaction

Answer:

D. The flesh should return to normal after you press it.

Explanation:

The water content stored in the flesh of the fish, paired with the elasticity are both indicators of freshness, and will cause the flesh to return to normal after its been pressed.

Answer:

0.77018342688495

Explanation:

I did this

Answer:

Two other beneficial properties of the oil include the inhibition of corrosion of metal surfaces, such as steel, and the removal of dirt and detritus via detergency.

Properties of water include its chemical formula H2O, density, melting, boiling point & how one molecule of water has two hydrogen atoms covalently bonded to one oxygen atom.