In a mass spectrum, there are two peaks, one at m/z 63.0 with percentage abundance 69.1% and another peak at m/z 65.0 with percentage abundance 30.9%. Determine the relative atomic mass (Ar) for this element, giving the answer to 3 significant figures (no units required).

Explanation:

temporary water is call carbonate hardness

parmanent water is call non-carbonate hardness

Temporary hardness is caused by the presence of dissolved bicarbonates of calcium, magnesium, and other heavy metals and the bicarbonates of iron.,The salts responsible for temporary hardness are Ca(HCO3)2 , Mg(HCO3)2

Permanent hardness It is due to presence of dissolved chlorides and sulphates of calcium, magnesium, iron and other heavy metals

(i) Liang - liang stoma lebih banyak di bahagian bawah daun berbanding di bahagian atas permukaan daun.

(ii) Struktur X berfungsi mangawal pembukaan dan penutupan liang stoma

Answer:

Aldehyde

Explanation:

1-bromo-1-1diphenylpropane

Answer:

Enthalpy and entropy. ... What would happen to the entropy in the reaction 2O3(g) 3O2(g)? It increases

What would happen to the entropy in the reaction 2O3(g) --> 3O2(g)?

It increases.

Vapourization and condensation. the actual 1 shud be vapourization.

Answer:

B. all organisms are made of at least one cell.

C.cells are the building blocks of life.

D.all cells come from preexisting cells

Explanation:

According to the cell theory that was proposed via the contribution of three scientists in 1830's namely: Matthias Schleiden, Theodor Schwann, and Rudolf Virchow, the following was stated:

- Cells are the basic and fundamental unit of life

- Living organisms are made up of one or more cells

- All cells arise from pre-existing cells.

From the above components, the following are said to be true and correlate with the universal cell theory:

B. all organisms are made of at least one cell.

C.cells are the building blocks of life.

D.all cells come from preexisting cells

Answer:

For a good consert mix aggregate needed to the clean hard strong partical free of absorb chemicals or coating clay and other fine materials

Answer: The number of moles of NaOH is 0.0036 moles

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Moles of solute}\times 1000}{ \text{Volume of solution (mL)}}[/tex] .....(1)

Given values:

Molarity of NaOH = [tex]0.1mol/dm^3=0.1mol/L[/tex]         (Conversion factor: [tex]1L=1dm^3[/tex]

Volume of the solution = [tex]36cm^3=36 mL[/tex]             (Conversion factor: [tex]1mL=1cm^3[/tex]

Putting values in equation 1, we get:

[tex]0.1=\frac{\text{Moles of NaOH}\times 1000}{36}\\\\\text{Moles of NaOH}=\frac{0.1\times 36}{1000}=0.0036mol[/tex]

Hence, the number of moles of NaOH is 0.0036 moles

Answer: The statement the  [tex]n^{th}[/tex] shell holds a minimum number of [tex]2n^{2}[/tex] electrons is true.

Explanation:

The alphabet 'n' denotes the principal quantum number whose value can be equal to 1, 2, 3, and so on but can never be zero.

Basically, 'n' is the number of shell of an atom and total number of orbitals present in a shell is [tex]n^{2}[/tex].

Each orbital can hold up to a maximum of wo electrons. Hence, the [tex]n^{th}[/tex] shell can hold a minimum number of [tex]2n^{2}[/tex] electrons.

Thus, we ca conclude that the statement the  [tex]n^{th}[/tex] shell holds a minimum number of [tex]2n^{2}[/tex] electrons is true.

Answer:

He supported the ideology of Marxism.

He opposed the tsar and was exiled.

He led the Bolsheviks.

Explanation:

Lenin was Russian Revolution political theorist. He served as first founding head of government of Soviet Russia. He supported the ideology of Marxism and opposed Tsar.

Answer:

It is the amount of energy needed to move an electric charge across a cell

Explanation:

Answer:

copper

Explanation:

so for this you can work out the mass for both and compare

so mass = moles × mr

so mass of sodium = 1 × 23= 23 g

and mass of copper = 1 × 63.5= 63.5 g

so copper have more mass :)

Answer:

solutions are homogeneous mixtures of two or more solutes in a solvent

solubility is the ability of a solute to dissolve in a solvent

Explanation:

hope this is helpful

Answer:

1. Jacques Charles

2. Temperature

3. Volume

4. Pressure

5. [tex] \frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Explanation:

Jacques Alexandre-César Charles was a French mathematician, scientist, inventor, balloonist, aeronaut, and physicist who was born on the 12th of November, 1746 in Beaugency, France and died on the 7th of April, 1823 in Paris, France. He was famously known for his invention of the first hydrogen balloon in 1783 and the discovery of Charles Law.

Charles states that when the pressure of an ideal gas is kept constant, the volume of the gas is directly proportional to the absolute temperature of the gas.

Mathematically, Charles' law is given by the formula;

[tex] VT = K[/tex]

[tex] \frac{V_{1}}{T_{1}} = \frac{V_{2}}{T_{2}}[/tex]

Where;

Answer: The volume of the solution is 85.7 mL

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

[tex]\text{Molarity of solution}=\frac{\text{Given mass of solute}\times 1000}{\text{Molar mass of solute}\times \text{Volume of solution (mL)}}[/tex] .....(1)

We are given:

Molarity of solution = 0.600 M

Given mass of [tex]BaSO_4[/tex] = 12.00 g

We know, molar mass of [tex]BaSO_4=[(1\times 137.33)+(1\times 32.07)+(4\times 16)]=233.4g/mol[/tex]

Putting values in equation 1, we get:

[tex]0.600=\frac{12.00\times 1000}{233.4\times \text{Volume of solution}}\\\\\text{Volume of solution}=\frac{12.00\times 1000}{233.4\times 0.600}=85.68mL=85.7mL[/tex]

The rule of significant number that is applied for the problems having multiplication and division:

The least number of significant figures in any number of the problem determines the number of significant figures in the answer.

Here, the least number of significant figures is 3 that is determined by the number, 0.600. Thus, the answer must have these many significant figures only.

Hence, the volume of the solution is 85.7 mL

Answer:

The second student is right.

Explanation:

The coyote feed on not only phalaropes but many other organisms present in the environment for its survival. There are many other organisms present in the ecosystem such as mice, squirrel, cactus fruit etc. The coyote feeds on phalaropes, the phalaropes feeds on brine shrimp and the brine shrimp feeds on algae for its survival so in this way the ecosystem moves in the forward direction. The coyote feeds on phalaropes so the energy that is present in phalaropes transferred into coyote which only 10 % while the remaining is released in the atmosphere in the form of heat energy.

Answer:

The mass percentage of chlorine is 60.66 % chlorine in the compound sodium chloride.

Explanation:

D. 8

Hope this helps! :)

______________

Answer:

D: 8 neutrons would make it most stable

Answer:

[tex]{ \bf{PV= \frac{m}{M} RT}} \\ \\ { \tt{(0.65 \times 23.52) = \frac{25}{M} \times 0.081 \times (25 + 273)}} \\ \\ M = 39.5 \: g[/tex]

Answer:

H2 + CaCl2 -> 2HCl + Ca

How many grams of HCl are made when 2.93 g of

Ca are made?

Explanation:

From the given balanced chemical equation, it is clear that:

2mol. of HCl and 1mol. of Ca are produced.

2mol. of HCl weighs --- 73.0g

1mol. of Ca weighs --- 40.0g

Hence,

73.0g of HCl and 40.0g of Ca are produced.

When 2.93g of Ca is produced then, how many grams of HCl will be produced?

[tex]=> 2.93g Ca * \frac{73.0g HCl}{40.0g Ca} \\=5.35g HCl[/tex]

Hence, 5.35g of HCl is formed.

Answer:

Radiation isn't beneficial to society .Radiation damages the cells that make up the human body. Low levels of radiation are not dangerous, but medium levels can lead to sickness, headaches, vomiting and a fever. High levels can kill you by causing damage to your internal organs. It's difficult to treat high radiation exposure.

Explanation:

Exposure to very high levels of radiation, such as being close to an atomic blast, can cause acute health effects such as skin burns and acute radiation syndrome (“radiation sickness"). It can also result in long-term health effects such as cancer and cardiovascular disease.

Radiation is both harmful and beneficial, but when we analyse it is found that harms overweight benefits. Radiation can be used as a form of energy (in nuclear plants), but an accident or malfunction in it can lead to death and injury of humans. Also, it is really difficult to dispose the used devices.

Answer:

Explanation:

what are the statments i can't help till i have the posable answers

Answer:

increase in the size of fruits and vegetables

Answer:

increased size of fruits or vegetables

Explanation:

Answer:

[tex]{ \tt{let \: the \: oxidation \: state \: be \: x}} \\ { \bf{x + sulphate \: ion+ water = overall \: charge}} \\ \\ \\ { \tt{x + ( - 2) + 0 = 0}} \\ \\ { \tt{x = + 2}} \\ { \tt{oxidation \: state = + 2}}[/tex]

Answer:

The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Mg(OH)2, or 58.31968 grams.

Answer:

B.

Explanation:

The electron dot diagram which is also known as the Lewis electron dot diagram is a diagram that shows an atom's valence electrons by placing dots, which represent the valence electrons of the element, around the elements symbol

The element for which the electron dot diagram is found = Neon, Ne

The atomic number of neon, Ne = 10

The electronic configuration of neon = 1s²2s²2p⁶

The valence shell is the outermost shell having   the highest value of the coefficient of the orbitals, n = 2s²2p⁶

The number valence electrons in neon = The number of electrons in the valency shell = 2 electrons + 6 electrons = 8 electrons

The number of valence electrons in neon = 8

Therefore, the electron dot diagram for neon will have 8 dots located around the Ne symbol, which gives option B