Answer:
b
Explanation:
because its the atom of the same element, the no of protons doesn't change but the mass number changes so we can find the mass number by:
(mass number = atomic no/no of protons + no of neutrons)
here;
mass number given = 65
and we know, no of protons = 29
let no of neutrons = x
hence,
65 = 29 + x
x= 65 – 29
x= 36
hence your answer is b
where is the atomic mass on the periodic table
Explanation:
At the upper left is the atomic number, or number of protons. In the middle is the letter symbol for the element (e.g., H). Below is the relative atomic mass, as calculated for the isotopes found naturally on Earth. At the very bottom is the name of the element (e.g., hydrogen).
It takes 25 mL of 0.20 M of hydrochloric acid (HCI) to neutralize 50 mL of
sodium hydroxide (NaOH). What is the concentration of sodium
hydroxide?
Answer:
0.1 M
Explanation:
(25 mL) (0.20 M) / 50 mL = 0.1 M
Which of the following is not a use of radioactive isotopes?
a) Energy generation
b) Carbon dating
c) Chemotherapy
d) Radiotherapy
Answer:
i belive the answer you are looking for is A.. hope this helps!
Explanation:
im not really 100% certain of this answer due to the fact i am a little rusty.
List THREE reasons why acidic soil can be a general problem to a natural ecosystem.
Answer:
Ok the poprtion would look like this : x 23
----------- = ----------
230 100
Explanation:
So for the last fill in it could be 52.9 or 60
i hope i got it correct lol pretty sure i did
Butane (C4 H10(g), Delta. Hf = â€"125. 6 kJ/mol) reacts with oxygen to produce carbon dioxide (CO2 , Delta. Hf = â€"393. 5 kJ/mol ) and water (H2 O, Delta. Hf = â€"241. 82 kJ/mol) according to the equation below. 2 upper C subscript 4 upper H subscript 10 (g) plus 13 upper o subscript 2 (g) right arrow 8 upper C upper O subscript 2 (g 0 plus 10 upper H subscript 2 upper O (g). What is the enthalpy of combustion (per mole) of C4H10 (g)? Use Delta H r x n equals the sum of delta H f of all the products minus the sum of delta H f of all the reactants. â€"2,657. 5 kJ/mol â€"5315. 0 kJ/mol â€"509. 7 kJ/mol â€"254. 8 kJ/mol.
The enthalpy of this reaction is -5315 KJ/mol.
The equation of the reaction is;
2C4H10(g) + 13O2(g) -----> 8CO2 (g) + 10H2O(g)
We know that the enthalpy of reaction can be obtained from the enthalpy of formation of the reactants and products as follows;
ΔHrxn = ΔHf(products) - ΔHf(reactants)
We have the following information from the question;
ΔHf C4H10 = - 125. 6 kJ/mol
ΔHf CO2 = - 393. 5 kJ/mol
ΔHf H2O = - 241. 82 kJ/mol
ΔHf O2 = 0 KJ/mol
Hence;
[(8 × (- 393. 5 )) + (10 × (- 241. 82))] - [2( - 125. 6))]
= -5315 KJ/mol
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what is the speed of a skater who travels a distance of 210 m in a time of 10 seconds
Answer:
Speed =d/t. 200÷10=21÷1000=0.021 km/h
Explanation:
S=D/T
Saliva, produced by glands in the mouth, plays an important role in the digestion of food. Saliva contains a chemical, called amylase, that breaks down starch in the food we eat. A scientist conducts an experiment to investigate at which temperatures amylase works the best. He hypothesizes that the reaction will occur fastest if the amylase reaction is conducted near the normal human body temperature of 37ºC (degrees Celsius). In order to test his hypothesis, the scientist measures the reaction rate, which is how fast the amylase breaks down the starch at six different temperatures. The reaction rate is rated on a scale of 0 to 10, with 0 meaning no reaction and 10 meaning the fastest reaction. The results are recorded in the data table.
AMYLASE REACTION RATE BY TEMPERATURE
Temperature (ºC)
Reaction Rate
0
2
20 4
40 10
60 8
80 2
100 0
Based on the data, should the scientist accept or reject his hypothesis?
Answer:
The digestive functions of saliva include moistening food, and helping to create a food bolus, so it can be swallowed easily. Saliva contains the enzyme amylase that breaks some starches down into maltose and dextrin. Thus, digestion of food occurs within the mouth, even before food reaches the stomach.
Explanation:
Which property determines whether a substance is a solid or liquid at room temperature?
Answer:
1. The kinetic energies of the particles (atoms, molecules, or ions) that make up a substance. Kinetic energy tends to keep the particles moving apart.
2. The attractive intermolecular forces between particles that tend to draw the particles together.
F
norm
app
F
grav
F
fric
Which statement is true in this situation?
A. The size of Ffric is the same as the size of Fgrav-
B. The size of Fnorm is the same as the size of Ffric
C. The size of Ffric is the same as the size of Fapp:
D. The size of F
app is the same as the size of Fgrav
The statement is true in this situation is C. The size of Ffric is the same as the size of Fapp:
From the diagram, since the body is in equilibrium, the sum of vertical forces equals zero. Also, the sum of horizontal forces equal zero.
So, ∑Fx = 0 and ∑Fy = 0
Since Fapp acts in the negative x - direction and Ffric acts in the positive x - direction,
∑Fx = -Fapp + Ffric = 0
-Fapp + Ffric = 0
Fapp = Ffric
Also, since Fgrav acts in the negative y - direction and Fnorm acts in the positive y - direction,
∑Fy = Fnorm + (-Fgrav) = 0
Fnorm - Fgrav = 0
Fnorm = Fgrav
So, we see that the size of Fapp equals size of Ffric and the size of Fnorm equals the size of Fgrav.
So, the correct option is C
The statement which is true in this situation is C. The size of Ffric is the same as the size of Fapp.
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1. In drawing Lewis structures, a single line (single bond) between two elements represents: ? a shared electron B. ? B 2 a shared pair of electrons c. ? an octet of electrons D. ? an unshared pair of electrons
Answer:
B a shared pair of electrons (2)
Explanation:
In Lewis structures, a single line represents a single pair of electrons. This means that the elements share 2 electrons or one pair of electrons
Hope this helps!
The shared electrons behave as if they belong to both atoms in the bond and bind the two atoms together to form a molecule. The shared electrons are typically depicted as a line (—) connecting the bonded atoms. (A line in a Lewis structure represents two electrons. Therefore, option A is correct.
What is lewis structure ?Lewis structures, also known as Lewis dot formulas, Lewis dot structures, electron dot structures, or Lewis electron dot structures, are diagrams that depict the bonding between atoms in a molecule as well as any lone pairs of electrons that may exist.
A Lewis structure is based on the octet rule, which states that atoms share electrons in order for each atom to have eight electrons in its outer shell. An oxygen atom, for example, has six electrons in its outer shell.
Gilbert N. Lewis, who introduced the Lewis structure in his 1916 article The Atom and the Molecule, was named after it. Lewis structures expand on the electron dot diagram concept by adding lines between atoms to represent shared pairs.
Thus, option A is correct.
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Is bleach liquid starch?
Yes or No
Answer:
O it's not
Explanation:
Have a great day!
How is a stable hydrogen atom different from every other atom?
Answer:
a hydrogen atom contains only one proton in it's nucleus, while atoms of all other elements contain more than one proton
Brainliest plzz
what was transferred from the hydrochloric acid to the water molecule
A proton (H⁺) is transferred from the hydrochloric acid to the water molecule.
What is Bronsted-Lowry theory?Bronsted-Lowry theory is used to classify acids and bases.
Acid: is a substance that donates H⁺.Base: is a substance that accepts H⁺.Hydrochloric acid is an acid and when it reacts with water, it transfers an H⁺ ion, according to the following equation.
HCl + H₂O ⇒ Cl⁻ + H₃O⁺
A proton (H⁺) is transferred from the hydrochloric acid to the water molecule.
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Where are nonmetals located in the periodic table?
Question 8 options:
along the upper left side
in the middle
along the upper right side
along the bottom
Answer: They are located along the upper right side of the periodic table.
Explanation: Malleability is a physical property that some elements of matter have that can be broken down into sheets to give them a certain shape without breaking. This physical property belongs to plasticity. It is a characteristic that some metals have, sheets of said metal can be obtained. The heat needs to be increased, some examples are gold, platinum, zinc, tin, etc.
PLEASE HELP ME I NEED HELP ASAP SO BADLY
Answer:
160.3 g S
Explanation:
What type of reaction takes place when using this enzyme (endergonic or exergonic)?
lactase is the enzyme
Answer:
we do the best possible in our
Which two elements have more protons per atom than phosphorus?
Answer:
nitrogen have more protons per atom than phosphorus
Oxygen and fluorine are the two elements that have more protons per atom than the element phosphorus.
What is phosphorus?Phosphorus (P), a nonmetallic chemical element of something like the nitrogen group (Group 15 [Va] of the periodic table), is a colorless, semitransparent, soft, sticky solid that glows in the dark at room temperature.
Hennig Brand, a German businessman with an interest in alchemy, appears to have discovered phosphorus around 1669. Brand left 50 buckets of pee alone till they putrified and "produced worms." He then reduced the urine to a paste and burned it with sand to extract elemental phosphorus first from combination. Oxygen and fluorine are the two elements that have more protons per atom than phosphorus.
Therefore, oxygen and fluorine are the two elements that have more protons per atom than phosphorus.
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How long is a bench? Select the best estimate.
4 centimeters
4 milllimeters
4 kilometers
4 meters
Answer:
4 meters
Explanation:
4 centimeters and millimeters are too small, while 4 kilometers is too large.
why does water boil at a lower temperature at higher altitudes
What is the formula of sulfur diphosphide
[tex] \huge \rm \ \blue \:{ \overbrace{ \underbrace{ \tt{ \color{red}{ \: \: \: \: \: \: answer \: \: \: \: \: \: }}}}}[/tex]
[tex] \huge \color{darkblue}P₂S_{5}[/tex]
hope it helpsAnswer:
P2S5
Explanation:
2NaOH(aq) + Cl2(g) -> NaCl(aq) + NaClO(aq) + H20(l)
Answer:
Cl2(g) + 2 NaOH(aq) = NaCl(aq) + NaClO(aq) + H2O(l)
Explanation:
What is the chemical reaction by which organisms break down food
molecules for energy?
Answer:
cellular respiration
Explanation:
hope this helps :)
brainliest plzzzzzzz
5. Scientists always develop a plan when they try to learn something about our natural world. Which
sequence correctly shows the steps scientists follow in their plan?
A. make observations, develop an idea, obtain evidence, suggest an explanation
B. obtain evidence, suggest an explanation, develop an idea, make observations
C. suggest an explanation, obtain evidence, make observations, develop an idea
D. develop an idea, suggest an explanation, obtain evidence, make observations
Michael was sitting at his desk one morning. He noticed a small spot of light on the wall
which moved with his arm. What could be causing this spot of light on the wall?
O a) light from the window being refracted
by his watch band
b) light from the window reflecting off the
face of his watch
O c) light from the window being absorbed
by the wall
d) light from his watch refracting on the
wall
Answer:
Light from the window reflecting off the face of his watch <33
Match each type of reaction to its amount of potential energy. (PLEASE HELP )
How many grams of LiF would need to be dissolved to make 400 mL of a 1.67 M solution?
Group of answer choices
30 g LiF
20 g LiF
10 g LiF
40 g LiF
Answer:
20g
Explanation:
hope helpful.............
It takes 60 mL of 0.20 M of sodium hydroxide (NaOH) to neutralize 25 mL of carbonic acid (H2CO3) for the following chemical reaction:
2 NaOH + H2CO3 → Na2CO3 + 2 H2O
The concentration of the carbonic acid is _____.
It requires 60 mL of 0.20 M sodium hydroxide [tex](NaOH)[/tex] to neutralize 25 mL of carbonic acid [tex](H_2CO_3)[/tex], hence the carbonate ions concentration is [tex]0.24M[/tex].
Given:
Reaction:
[tex]\to \bold{2NaOH + H_2CO_3 \to Na_2CO_3 + 2H_20 }[/tex]
[tex]NaOH[/tex] volume [tex](V_B) = 60 \ ml[/tex]
[tex]H_2CO_3[/tex] Volume [tex](V_A) = 25\ ml[/tex]
[tex]NaOH[/tex] Molarity [tex](C_B) = 0.20\ M[/tex]
[tex]H_2CO_3[/tex] moles [tex](n_A) = 1[/tex]
[tex]NaOH[/tex] moles [tex](n_B) = 2[/tex]
To find:
[tex]H_2CO_3[/tex] Molarity [tex](C_A) =?[/tex]
Solution:
Using the neutralization reaction:
[tex]\to \frac{C_AV_A}{C_BV_B} =\frac{n_A}{n_B} \\\\[/tex]
[tex]\to C_B = 0.2\ M \\\\ \to n_A = 1 \\\\ \to n_B = 2 \\\\ \to V_B = 60\ ml \\\\ \to V_A = 25\ ml[/tex]
Calculating the [tex]C_A[/tex]:
[tex]\to \frac{C_A \times 25}{0.2 \times 60} =\frac{1}{2} \\\\\to C_A =\frac{1 \times 0.2 \times 60}{2 \times 25} \\\\\to C_A =\frac{1 \times 2 \times 12}{2 \times 5 \times 10} \\\\ \to C_A =\frac{ 12}{ 5 \times 10} \\\\\to C_A = \frac{6}{5 \times 5} \\\\\to C_A = \frac{6}{25} \\\\\to C_A=0.24\ M[/tex]
Therefore, the concentration of carbonic acid is "0.24M".
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The concentration of carbonic acid( H₂CO₃) is 0.24 M.
The given reaction:
2 NaOH + H₂CO₃ → Na₂CO₃ + 2H₂O
Volume of NaOH = 60mL
Volume of H₂CO₃ = 25 mL
Molarity of NaOH= 0.20M
To find:
Molarity of H₂CO₃=?
2 moles of NaOH and 1 mol of H₂CO₃ reacts to give 1 mol of Na₂CO₃.
Using the neutralization reaction:
Consider A to be NaOH and B to be H₂CO₃
[tex]\frac{\text{Number of moles of A}}{\text{Number of moles of B}} =\frac{\text{Molarity of A*Volume of A}}{\text{Molarity of B*Volume of B}}[/tex]
On substituting the values in order to calculate molarity of H₂CO₃:
[tex]\text{Molarity of B}=\frac{1*0.2*60}{2*25} \\\\\text{Molarity of B}=0.24M[/tex]
Therefore, the concentration of H₂CO₃ is 0.24 M.
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How many molecules are present in this formula? 3H2 (SO)4
Molecules are formed when two or more atoms chemically bond together. In 3H₂(SO)₄, three molecules are present.
What are molecules?Molecules are the smallest unit present in any compound and are formed by a group of atoms. A number denoted in front of the chemical species is the coefficient that represents the number of molecules.
The coefficient present in front of the reactant or the product in a chemical reaction gives the number of the molecules present in a compound. As three is denoted in front of the sulphuric acid, hence will be the number of the molecules.
Therefore, there are three molecules present in sulphuric acid.
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How much heat is required to warm 50.0 g of ice from -10.0oC to 0.00oC, melt the ice, warm the water from 0.00oC to 100.0oC, boil the water, and heat the steam to
120.0oC ?
a 209,000 J
b 199,000 J
c 1.67 x 106 J
d 152,000 J
The total heat required to convert the ice to steam is 155,000 J.
The given parameters:
Mass of the ice, m = 50 gInitial temperature of the ice, t = -10 ⁰CFinal temperature of the ice, T = 0⁰C, 100⁰C and 120⁰CSpecific heat capacity of water = 4.184 J/g⁰CHeat of fusion of ice, = 333.55 J/gHeat of vaporization, = 2,230 J/gThe heat required to raise the temperature to 0⁰C is calculated as;
[tex]Q = mc\Delta t\\\\Q_1 = 50 \times 4.184 \times (0 - (-10))\\\\Q_1 = 2092 \ J[/tex]
The heat required to melt the ice is calculated as follows;
[tex]Q_2 = mL_f\\\\Q_2 = 50 \times 333.55 \\\\Q_2 = 16,677.5 \ J[/tex]
The heat raise the temperature to 100⁰C is calculated as;
[tex]Q_3 = 50 \times 4.184 \times (100 - 0)\\\\Q_3 = 20,920 \ J[/tex]
The heat required to boil the water is calculated as follows;
[tex]Q_4 = mL_v\\\\Q_4 = 50 \times 2230\\\\4_4 = 111,500 \ J[/tex]
The heat raise the temperature to 120⁰C is calculated as;
[tex]Q_5 = 50 \times 4.184 \times (120 - 100)\\\\Q_5 = 4,184 \ J[/tex]
The total heat required is calculated as follows;
[tex]Q_t = Q_1 + Q_2 + Q_3 + Q_4 + Q _5 \\\\Q_t = 2092 + 16,677.5 + 20,920 + 111,500 + 4,184\\\\Q_t = 155,373.5 \ J\\\\Q_t \approx 155,000 \ J[/tex]
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ILL MARK AS BRAINIEST AND GIVE YOU 30 POINTS!!!
Answer:
did u get it yet
Explanation: