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Answer:

0.3125 g

Explanation:

Given data:

Half life of barium-122 = 2 min

Mass of sample = 10.0 g

Mass of barium remain after 10 min = ?

Solution:

Number of half lives = Time elapsed / half life

Number of half lives = 10 min/ 2 min

Number of half lives = 5

At time zero = 10 g

At 1st half life = 10 g/2 = 5 g

At 2nd half life = 5 g/2 = 2.5 g

At 3rd half life = 2.5 g/2 = 1.25 g

At 4th half life = 1.25 g/2 = 0.625 g

At 5th half life = 0.625 g/2 = 0.3125 g

Answer:

Elements are the simplest complete chemical substances. Each element corresponds to a single entry on the periodic table. An element is a material that consists of a single type of atom. Each atom type contains the same number of protons.

Chemical bonds link elements together to form more complex molecules called compounds. A compound consists of two or more types of elements held together by covalent or ionic bonds.

Explanation:

Answer:

CaCl₂ (aq) + 2NaOH (aq) —> Ca(OH)₂ (s) + 2NaCl (aq)

Explanation:

The equation for the reaction is given below:

CaCl₂ (aq) + NaOH (aq) —> Ca(OH)₂ (s) + NaCl (aq)

The above equation can be balance by as follow:

CaCl₂ (aq) + NaOH (aq) —> Ca(OH)₂ (s) + NaCl (aq)

There are 2 atoms of Cl on the left side and 1 atom on the right side. It can be balance by putting 2 in front NaCl as shown below:

CaCl₂ (aq) + NaOH (aq) —> Ca(OH)₂ (s) + 2NaCl (aq)

There are 2 atoms of Na on the right side and 1 atom on the left side. It can be balance by putting 2 in front of NaOH as shown below:

CaCl₂ (aq) + 2NaOH (aq) —> Ca(OH)₂ (s) + 2NaCl (aq)

Now, the equation is balanced.

Answer:

20 protons.

Explanation:

20 protons = 20 + charges

18 electrons = 18- charges.

The difference = 20 - 18 = +2

The charge for this ion is plus 2

It is a calcium ion. The element is number 20 on the periodic table.

The charge of the ion is +2

HOW TO DETERMINE THE CHARGE OF AN ION:

Therefore, the charge of the ion will be 20 protons - 18 electrons = +2

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Answer:

Explanation:

the moon is still volcanic

Answer:

162.4

Explanation:

The formula for mass is density* volume so 62.7 multiplied by 2.59 equals 162.393. then you round so your anwser would be 162.4

Answer:

False

Explanation:

It is the other way round, a black object appears black because it absorbs all the wavelength of light and does not reflect any light.

Answer:

1. The pH of 1.0 M trimethyl ammonium (pH = 1.01) is lower than the pH of 0.1 M phenol (5.00).

2. The difference in pH values is 4.95.

Explanation:

1. The pH of a compound can be found using the following equation:

[tex] pH = -log([H_{3}O^{+}]) [/tex]

First, we need to find [H₃O⁺] for trimethyl ammonium and for phenol.

Trimethyl ammonium:

We can calculate [H₃O⁺] using the Ka as follows:

(CH₃)₃NH⁺ + H₂O  →  (CH₃)₃N + H₃O⁺    

1.0 - x                               x           x  

[tex]Ka = \frac{[(CH_{3})_{3}N][H_{3}O^{+}]}{[(CH_{3})_{3}NH^{+}]}[/tex]

[tex] 10^{-pKa} = \frac{x*x}{1.0 - x} [/tex]

[tex] 10^{-9.80}(1.0 - x) - x^{2} = 0 [/tex]    

By solving the above equation for x we have:  

x = 0.097 = [H₃O⁺]

[tex] pH = -log([H_{3}O^{+}]) = -log(0.097) = 1.01 [/tex]                                      

Phenol:

C₆H₅OH + H₂O → C₆H₅O⁻ + H₃O⁺

1.0 - x                        x             x

[tex]Ka = \frac{[C_{6}H_{5}O^{-}][H_{3}O^{+}]}{[C_{6}H_{5}OH]}[/tex]

[tex] 10^{-10} = \frac{x^{2}}{1.0 - x} [/tex]

[tex] 1.0 \cdot 10^{-10}(1.0 - x) - x^{2} = 0 [/tex]

Solving the above equation for x we have:

x = 9.96x10⁻⁶ = [H₃O⁺]

[tex] pH = -log([H_{3}O^{+}]) = -log(9.99 \cdot 10^{-6}) = 5.00 [/tex]

Hence, the pH of 1.0 M trimethyl ammonium is lower than the pH of 0.1 M phenol.

2. The difference in pH values for the two acids is:

[tex] \Delta pH = pH_{C_{6}H_{5}OH} - pH_{(CH_{3})_{3}NH^{+}} = 5.00 - 1.01 = 4.95 [/tex]

Therefore, the difference in pH values is 4.95.

I hope it helps you!

Answer:

Inductive reasoning

Explanation:

Inductive reasoning is based on making broad generalizations from specific observations. We draw conclusions from the data we have. This is the opposite of deductive reasoning, which starts with a general statement and aims to reach a specific conclusion.

Based on this, we can conclude that, if an investigator uses their knowledge, training, experience, and expertise to reach a conclusion, they are using inductive reasoning.

Answer:

[tex]\%\ Error = 21.5\%[/tex]

Explanation:

Given

[tex]Measured = 24.5[/tex]

[tex]Actual = 31.2[/tex]

Required

Determine the percentage error

First, we need to determine the difference in the measurement

[tex]Difference = |Actual - Measured|[/tex]

[tex]Difference = |31.2 - 24.5|[/tex]

[tex]Difference = |6.7|[/tex]

[tex]Difference = 6.7[/tex]

The percentage error is calculated as thus:

[tex]\%\ Error = \frac{Difference * 100\%}{Actual}[/tex]

[tex]\%\ Error = \frac{6.7 * 100\%}{31.2}[/tex]

[tex]\%\ Error = \frac{670\%}{31.2}[/tex]

[tex]\%\ Error = 21.4743589744\%[/tex]

[tex]\%\ Error = 21.5\%[/tex] approximated

Answer:

D - Nucleus to Cell

Explanation:

Hope it helps!!

:D

Answer:

653 gH³PO⁴

Explanation:

We'll first write the chemical equation for this reaction:

P

4

O

10

(

s

)

+

6

H

2

O

(

l

)

→

4

H

3

PO

4

(

a

q

)

Let's now find the relative number of moles of phosphoric acid (

H

3

PO

4

) using the coefficients of the equation, and the fact that

10.0

mol H

2

O

react:

10.0

mol H

2

O

(

4

l

mol H

3

PO

4

6

mol H

2

O

)

=

6.67

mol H

3

PO

4

Now, using the molar mass of

H

3

PO

4

(calculated to be

98.00

g/mol

), let's find the theoretical mass of phosphoric acid produced:

6.67

l

mol H

3

PO

4

(

98.00

l

g H

3

PO

4

1

mol H

3

PO

4

)

=

653

mol H

3

PO

4

Thus, if the reaction goes to completion, there will be a yield of

653

grams of phosphoric acid

Thank me later

Mark me as brainliest please for my answer

Answer:

Protons,electrons,and neutrons make up matter

Explanation:

i studied this so hope it helps

Answer:

A graph can be very handy in collecting data and storing it in one place. A graph can be a very effective tool in presenting visual information rather swiftly. Hope this helps! I am learning about graphs in my course!

Explanation:

Answer:

graph) a diagram showing the relation between variable quantities, typically of two variables, each measured along one of a pair of axes at right angles.

Explanation:

Graphing is used daily. From stockbrokers to performance evaluation in companies. All use them to boost sales and meet deadlines. Even simple calculations can be assessed better by using a graph.

(let me know if this helps?)

Answer:If you are sedentary (little or no exercise) : Calorie-Calculation = BMR x 1.2.

If you are lightly active (light exercise/sports 1-3 days/week) : Calorie-Calculation = BMR x 1.375.

Explanation:

Answer:

CO < BF < KI < LiF

Explanation:

The magnitude of ionic character in a bond is dependent on the magnitude of electronegativity difference between the atoms in the bond.

Remember that no bond is 100% ionic or covalent according to Linus Pauling. However, the percentage ionic character depends on electronegativity difference between the bonding atoms and polarizability (Fajan's rules).

Between LiF and KI, Fajan's rules become very important. The Li^+ is small and highly polarizing.  The stronger the polarising power of the cation and the higher the polarisability of the anion the more covalent character is expected in a bond

Answer:

15.9994 grams

You can view more details on each measurement unit: molecular weight of Oxygen or grams The molecular formula for Oxygen is O. The SI base unit for amount of substance is the mole. 1 mole is equal to 1 moles Oxygen, or 15.9994 grams.

Explanation:

Answer:

First you need to know the Chemical formula for Nitrous acid which is HNO₂

Explanation:

Answer:

look at the explanation

Explanation:

The air that you breathe is a homogeneous mixture of oxygen, nitrogen, argon, and carbon dioxide, along with other elements in smaller amounts. Because each layer of the Earth's atmosphere has a different density, each layer of air is its own homogeneous mixture.

Hope this helps. :)

Answer: 2681.81

Explanation:

9

Answer:

Pb, Cr, Fe

Explanation:

The metals that can react with hydrochloric acid are; Sn, Cr and Ni.

The electrochemical series shows the reactivity of elements. An element can only replace another element in solution when that element is higher in the electrochemical series.

The metals that can replace hydrogen in a solution of hydrochloric acid must be metals that are above hydrogen in the electrochemical series. These metals are; Sn, Cr and Ni. Hg is a noble metal hence it does not replace hydrogen in an acid solution.

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Answer:

C

Explanation:

Hope this helps :)

Answer:

iodine pentachloride

Explanation:

The answer is 80N

(hope this helps you!!!)

Answer:

11.86%

Explanation:

First, we convert both solvent and solute to the same unit, say, kg. We have.

Mass of Sodium Bicarbonate = 7g = 7/1000 kg = 0.007 kg

Mass of water = 0.052 kg.

Formula for the mass percent is

% of sodium bicarbonate = [(mass of sodium bicarbonate) / (mass of total solution) * 100%]

Total mass of solution = 0.007 + 0.052 Total mass of solution = 0.059

% of sodium bicarbonate = 0.007 / 0.059 * 100%

% of sodium bicarbonate = 11.86%

Therefore, the mass percent of sodium bicarbonate I'm the solution is 11.86%