Answer:
(i) Protons, Neutrons
(ii) Mass number = 15
(iii) Atomic number = 12
(iv) Neutrons present in the atom = 17
(v) Nuclear symbol for the silicon isotope with mass number, A = 29 is ²⁹₁₄Si
Explanation:
(i) An atom is composed of three fundamental sub-particles: electrons, protons and neutrons. Electrons are found in orbits or energy levels some distance away from The nucleus of the atom. The nucleus of an atom contains the protons and neutrons which accounts for the mass of the atom.
(ii) The mass number of an atom of an element is the sum of the protons and neutrons present jn the nucleus of the atom.
The mass number of an atom of oxygen with proton or atomic number 8 and neutron number 7 is 8 + 7 = 15
(iii) Atomic number of an atom of an element is equal to the number of protons in the atom of the element.
Mass number = proton number + neutron number
Proton number = mass number - proton number
Proton number = 25 - 13 = 12
(iv) In the atom of sulfur represented bymthe symbol, the number in superscript is the mass number A, and the number in subscript is the atomic number Z.
Mass number = proton number + neutron number
Neutron number = Mass number - proton number
Neutron number = 33 - 16 = 17
(v) The nuclear symbol for the silicon isotope with mass number, A = 29 is ²⁹₁₄Si
Where the number in superscript is the mass number A, and the number in subscript is the atomic number Z.
What happens when one adds (NH4)2S to a solution that contains Al3+? What are the products of the chemical reaction?
Answer:
What happens when one adds (NH4)2S to a solution that contains Al3+?
Explanation:
When a solution that contains [tex]Al^{3+}[/tex] reacts with ammonium sulfide solution, then a precipitate of aluminum sulfide is formed.
The chemical equation for the reaction is shown below:
[tex]3(NH_{4})_{2} S(aq)+2 Al^{3+}(aq) -> Al_{2} S_3} (s) +3 NH_{4}^{+}[/tex]
examples of elements
In some chemical reactions, such as photosynthesis, several different compounds take part in the reaction. How do you think that atoms present at the end of this kind of reaction compare to the atoms present at the beginning of the reaction? Explain.
Answer:
The atoms present at the beginning of the reaction is equal to the atoms present at the end of the reaction. This is because matter can neither be created nor be destroyed in an ordinary chemical reaction.
Explanation:
During photosynthesis, 6 molecules of water react with 6 molecules of carbon dioxide to form 1 molecule of glucose and 6 molecules of oxygen. The equation for the photosynthesis reaction is
6CO2 + 6H2O --> C6H12O6 + 6O2
At the beginning of the reaction, there is 6 carbon atoms, 18 oxygen atoms and 12 hydrogen atoms while at the end of the reaction, there is 6 carbon atoms, 12 hydrogen atoms and 18 oxygen atoms. This is because according to the law of conservation of mass and matter, it can neither be created nor be destroyed in an ordinary chemical reaction. The number of atoms present at the beginning of the reaction must be equal to the number of atoms present at the end of the reaction.
What is the main source of energy in stars?
A. Combustion
B. Gravity
C. Fission
D. Fusion
Answer:
D. Fusion
Explanation:
D. Fusion
Hope this helps! :)
which synthetic fiber feels like wool and used as a substitute for wool
Answer:
Acrylic
Acrylic is the synthetic fibre feels like wool and used as a substitute for wool.
Please answer. Brainliest!
Answer:
the equation is balanced
Explanation:
the equation is balanced
Explanation:
the equation is blanced
50 ml of 0.2 M acetic acid is shaken with 10 g activated charcoal. The concentration of acetic acid is reduced to 0.5 times the original molarity. The amount of solute (in g) adsorbed per gram of the adsorbent is approximately
Answer:
[tex] 0.03 g_{acid}/g_{charcoal} [/tex]
Explanation:
The amount adsorbed (solute) is the acetic acid, and the adsorbent is the activated charcoal. The mass of the adsorbent is 10 g.
So, we need to calculate the mass of the acetic acid as follows:
[tex] m = n*M = C*V*M [/tex]
Where:
n: is the number of moles = C*V
M: is the molecular mass = 60.052 g/mol
C: is the final concentration of the acid = 0.5*0.2 mol/L = 0.10 mol/L
V: is the volume = 50 ml = 0.050 L
[tex] m_{acid} = C*V*M = 0.10 mol/L*0.050 L*60.052 g/mol = 0.30 g [/tex]
Now, the amount of solute adsorbed per gram of the adsorbent is:
[tex] \frac{m_{acid}}{m_{charcoal}} = \frac{0.30 g}{10 g} = 0.03 g_{acid}/g_{charcoal} [/tex]
Therefore, the amount of solute adsorbed per gram of the adsorbent is 0.03 g/g.
I hope it helps you!
While molecules such as glucose move freely in the blood, triglycerides are carried in the blood by very low density lipoproteins (VLDLs) in the form of chylomicrons. A chylomicron resembles a droplet, with phospholipid heads and VLDLs facing water, the solvent of blood, while triglycerides are found within. The outer surface resembles that of a regular phospholipid bilayer. If the contents of a chylomicron are all lipids
A. then they should be soluble in blood plasma.
B. an inner layer is needed because phospholipids always form bilayers,
C. there is no need for an inner phospholipid layer in a chylomicron
Answer:
B. an inner layer is needed because phospholipids always form bilayers.
Explanation:
Lipids are organic compounds which are not soluble in water but they are soluble in organic compounds. They are formed in body by combination of various molecules. The inner layer of phospholipids always form bilayers.
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Answer:
3rd or 4th answer is correct
OPTION B is the correct answer
ANSWER THIS FOR 15 POINTS!!!
A hot metal plate at 150°C has been placed in air at room temperature. Which event would most likely take place over the next few minutes?
Molecules in both the metal and the surrounding air will start moving at lower speeds.
Molecules in both the metal and the surrounding air will start moving at higher speeds.
The air molecules that are surrounding the metal will slow down, and the molecules in the metal will speed up.
The air molecules that are surrounding the metal will speed up, and the molecules in the metal will slow down.
Answer:
it is the last one
Explanation:
cause over time the meatl will imit heat and heat up the air around it as it cools down slowly
How many meters are in 37 cm?
0.37 m
0.037 m
3700 m
370 m
Answer:
the correct answer is 0.37m
Explanation:
37/100 = 0.37m
Answer:
How many meters are in 37 cm?
In 37 cm - 0.37 m
>3
Grasses, shrubs, and tree are called producers because they make
A. Food
B. water
C. Carbon dioxide
D. Minerals
a what is acrylic
b state the important use of acrylic fiber
can someone pls tell me if this is correct? and also if possible, pls explain the difference between fractional and simple distillation, thank you sm <3
Explanation:
everything can be found in the picture
When looking for a mathematical relationship between two variables, use a _____.
Answer:
Use a line graph
Explanation:
Which of the following pairs lists a substance that can neutralize H2SO4 and the salt that would be produced from the reaction?
O CaOH2 and Ca(SO4)2
OLIOH and Li2SO4
ONH, and NH,SO4
O NH3 and (NH3)2SO4
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Answer: b
Explanation:
I took the test
The correct answer is LiOH and Li2SO4.
A strong acid is neutralized by a strong base to yield a normal salt.
A neutralization reaction is a reaction between an acid and a base to yield salt and water only.
An acid can be strong or weak. A base can also be strong or weak. "Strong" or "weak" has to do with the extent of ionization of the acid or base in water. Usually, a strong acid is neutralized by a strong base.
Since H2SO4 is a strong acid, it will require a strong base such as LiOH to neutralize it and the product will be the normal salt Li2SO4.
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Consider the two facts below:
Fact 1: Dissolved oxygen is one of the most
important nutrients needed by fish in the aquatic
environment to survive.
Which scenarios may be explained by the facts on
the left? Check all that apply.
ID There is more dissolved oxygen in colder
waters than in warm water.
IM
Fact 2: Unlike solids, whose solubility increases
with increasing temperature, the solubility of gases
generally decreases with increasing temperature.
IND
There is less dissolved oxygen in colder
waters than in warm water.
Fish life in the ocean is more abundant during
the seaons with warmer water than seasons
with cooler water
HII
If ocean temperatures rise, then the risk to
the fish population increases.
DONE W
Answer:
A. There is more dissolved oxygen in colder waters than in warm water.
D. If ocean temperature rise, then the risk to the fish population increases.
Explanation:
Conclusion that can be drawn from the two facts stated above:
*Dissolved oxygen is essential nutrient for fish survival in their aquatic habitat.
*Dissolved oxygen would decrease as the temperature of aquatic habit rises, and vice versa.
*Fishes, therefore, would thrive best in colder waters than warmer waters.
The following are scenarios that can be explained by the facts given and conclusions arrived:
A. There is more dissolved oxygen in colder waters than in warm water (solubility of gases decreases with increase in temperature)
D. If ocean temperature rise, then the risk to the fish population increases (fishes will thrive best in colder waters where dissolved oxygen is readily available).
Answer: the answers are A and D
Explanation:
i got it right
what are some ways you would expect people and things to be affected by an earthquake that moved the ground that much?
Answer:
Some of the common impacts of earthquakes include structural damage to buildings, fires, damage to bridges and highways, initiation of slope failures, liquefaction, and tsunami.
Which of the following would be expected to have the lowest boiling point?
CH3CH2CH2CH3, CH3CH2NHCH3, NH2CH2CH2NH2, CH3CH2CH2NH2
O CH3CH2NHCH3
O NH2CH2CH2NH2
O CH3CH2CH2NH2
O CH3CH2CH2CH3
Answer:
CH3CH2CH2CH3
Explanation:
The boiling point of a compound depends on the nature of intermolecular interaction between the molecules of the compound.
If a molecule is nonpolar and has a low molecular mass, then its molecules are most likely held together only by weak intermolecular bonds such as dispersion forces. These forces are easily broken and the molecules move apart hence the molecule possess a low boiling point.
Polar molecules and molecules having higher molecular mass tend to have higher boiling points.
Among all the compounds listed, CH3CH2CH2CH3 is non polar and has the lowest molecular mass hence it exhibits the least boiling point.
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c) Current cannot flow
Reason: Because the switch is not closed.
Answer:
current can't flow
Explanation:
by the way of explanation it is open circuit in which the current flow whereas in closed circuit the current flow.
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it will be too much help for me.
what is the pound mole of co2
Equation balancing a. S(s) + O2(g) → SO3(8) b. 2Al(s) + 3C12(8) ► 2AICI,(s) E. 2NaOH(s) + H2SO,(ac) —Na,SO (ac) + H2O(1) d. CHg(8) + 50(8) - A 3C02(8) + 4H2O(g)
Answer:
a. S(s) + 3/2 O₂(g) → SO₃(g)
b. Al(s) + 3/2 Cl₂(g) → AICI₃(s)
c. 2 NaOH(s) + H₂SO₄(ac) → Na₂SO₄(ac) + 2 H₂O(l)
d. C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(g)
Explanation:
We will balance the equation using the trial and error method.
a. S(s) + O₂(g) → SO₃(g)
1. We will balance O atoms by multiplying O₂by 3/2.
S(s) + 3/2 O₂(g) → SO₃(g)
b. Al(s) + Cl₂(g) → AICI₃(s)
1. We will balance Cl atoms by multiplying Cl₂ by 3/2.
Al(s) + 3/2 Cl₂(g) → AICI₃(s)
c. NaOH(s) + H₂SO₄(ac) → Na₂SO₄(ac) + H₂O(l)
1. We will balance Na atoms by multiplying NaOH by 2.
2. We will balance H and O atoms by multiplying H₂O by 2.
2 NaOH(s) + H₂SO₄(ac) → Na₂SO₄(ac) + 2 H₂O(l)
d. C₃H₈(g) + O₂(g) → CO₂(g) + H₂O(g)
1. We will balance C atoms by multiplying CO₂ by 3.
2. We will balance H atoms by multiplying H₂O by 4.
3. We will balance O atoms by multiplying O₂ by 5.
C₃H₈(g) + 5 O₂(g) → 3 CO₂(g) + 4 H₂O(g)
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C3H8(g)+5O2(g)→3CO2(g)+4H2O(g)(propane)
CH4 + 2O2 → CO2 + 2H2O. (Methane)
2C4 H10 + 13O2 → 8CO2 + 10H2 O.(butane)
Which of the following is a method that transports eroded material?
please show step by step and I will mark you as brainliest answer ❤️
Answer: The pH of the solution is 13.
Explanation:
pOH is defined as the negative logarithm of hydroxide ion concentration present in the solution.
[tex]pOH=-\log [OH^-][/tex]
We are given:
Concentration of [tex]Ca(OH)_2=0.05mol/dm^3=0.5mol/L[/tex] (Conversion factor: [tex]1L = 1dm^3[/tex] )
1 mole of calcium hydroxide produces 1 mole of calcium ions and 2 moles of hydroxide ions
Concentration of [tex]OH^-=(2\times 0.05)=0.1mol/L[/tex]
Putting values in above equation, we get:
[tex]pOH=-\log (0.1)\\\\pOH=1[/tex]
We know:
[tex]pH+pOH=14\\\\pH=14-1\\\\pH=13[/tex]
Hence, the pH of the solution is 13.
How many molecules of SO3 are present in 48g of SO3?
Answer:
3.6 ×10^23
Explanation:
moles = mass/ molar mass
molar mass= (1×32) +(3×16)= 80
moles = 48/ 80
=0.6
moles = number of molecules/ 6×10^23
number of molecules = moles × 6×10^23
=0.6 × 6×10^23
=3.6 ×10^23
How many places after the decimal should your measurements contain?
Answer:
Minimum 2. ( Thats how I do, and till now there is no probs)
Thank You'
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According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on which factor?
Answer:
Temperature.
Explanation:
Kinetic molecular theory of gases states that gas particles exhibit a perfectly elastic collision and are constantly in motion.
According to the kinetic-molecular theory, the average kinetic energy of gas particles depends on temperature.
This ultimately implies that, the average kinetic energy of gas particles is directly proportional to the absolute temperature of an ideal gas. Thus, an increase in the average kinetic energy of gas particles would cause an increase in the absolute temperature of an ideal gas.
Temperature can be defined as a measure of the degree of coldness or hotness of a physical object. It is measured with a thermometer and its units are Celsius (°C), Kelvin (K) and Fahrenheit (°F).
Complete the following statements to describe solids, liquids, and gases. Select the correct answer fror
A solid
A liquid
A gas
va definite volume and
a definite volume and
a definite volume and
v
a definite shape.
a definite shape.
a definite shape.
Answer:
solid is definite volume and shape
liquid is a definite volume but not a definite shape because it can move around and fit into different shapes, like on different water bottles.
gas is not a definite volume and not a definite shape because gas particles can expand and spread out which affects both volume and shape
The formation of a gaseous product is usually indicated by a/an______________ in a chemical reaction.
Answer: The formation of a gaseous product is indicated by an UPWARD ARROW in a chemical reaction.
Explanation:
A chemical reaction is defined as the process whereby chemical bonds between atoms of
substances known as reactants are either formed or broken leading to the formation of products. New substances are usually formed during a chemical reaction. The following are features of chemical reaction:
--> Evolution of gas
--> Formation of a precipitate
--> Change in color
--> Change in temperature
--> Change in state and
--> Formation of new substances.
Some chemical reactions takes place with the evolution of gas. This can be seen in the reaction of Zinc metal with hydrochloric acid. Hydrogen gas is EVOLVED with the formation of zinc chloride.
UPWARD ARROW in a chemical reaction indicates the evolution of a gas. It appears only on the product side and is written next to the gaseous product.