Answer:
60.7%
Explanation:
Molar mass of NaCl = 23 +35.5
= 58.5 g/mol
Molar mass of Cl = 35.5 g/mol
Percentage by mass of Cl =?
The percentage by mass of Cl in NaCl can be obtained as shown below'
Percentage by mass = mass of element / mass of the compound × 100
Percentage by mass of Cl
= 35.5 / 58.5 × 100
= 3550 / 58.5
= 60.7%
Therefore, the percentage by mass of Cl in NaCl is 60.7%
what is the purpose of environmental regulations on chemicals
Answer: EPA regulates the production and distribution of commercial and industrial chemicals, in order to ensure that chemicals for sale and use in the United States do not harm human health or the environment.
Explanation:
state and explain the trends in the atomic radius and ionization energy for elements Li to Cs.
Explanation:
ionisation energy decrease down the group as the atomic radius increases. Nuclear charge increases. Number of shell increases so the electron will experience more shielding so it would be easier for the atom to loss electron.
how much energy (in joules) is needed to change 45.0 grams of ice at -25.0 C to water at 49 C?
Explanation:
The heat required to convert 25 grams of -10 °C steam is 78360 J or 78.36 kJ.
Alpha particles cannot penetrate the skin. In which of the following circumstances could they still threaten human health?
A. If they travel into the human eye.
B. If they are inhaled or swallowed.
C. If they enter into the human ear.
D. If they are touched.
Answer:
B. If they are inhaled or swallowed.
Figure 1 (Use this figure to answer questions 6,7, and 8. Assume that the height at point
A and point C are the same)
С
B
As the car moves from point A, to point B, and finally to point C, the total energy of the car
decreases from point A to point B, then increases from point B to point
increases from point A to point B, then decreases from point B to point
O is lost between points B and C
stays the same, but is converted between potential and kinetic energy
Answer:
JWBVH
Explanation:
NWSBWHSBHS
If 3.02 g of CuNO3 is dissolved in water to make a 0.560 M solution, what is the volume of the solution in milliliters?
Answer: The volume of the solution is 28.75 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)
Given values:
Molarity of copper nitrate = 0.560 M
Given mass of copper nitrate = 3.02 g
Molar mass of copper nitrate = 187.56 g/mol
Putting values in equation 1, we get:
[tex]0.560=\frac{3.02\times 1000}{187.56\times \text{Volume of solution}}\\\\\text{Volume of solution}=\frac{3.02\times 1000}{187.56\times 0.560}=28.75mL[/tex]
Hence, the volume of the solution is 28.75 mL
The nth shell holds a minimum number of 2n2 electrons
True
False
Other:
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.
How do the Carnivorous plants survive without soil?
Answer:
A simple answer: Carnivores don't eat plants only flesh. So they would not need soil. But it would be hard for Carnivores to get energy because they get energy indirectly from the animals (herbivores) that they eat. How do they get the energy from a herbivore you might ask. Herbivores eat only plants and that gives the herbivore the plant's energy; but if the herbivore gets eaten, it is indirectly transferred into the Carnivore. Hope this helped!!
Carnivore = only feeds on flesh
Herbivore = eats only plants
Omnivore = eats plants and animals/flesh
The absorption spectrum of sodium has a line at 589 nm. What is the energy of this line? (The speed of light in a vacuum is 3.00 x 10^8 m/s, and Planck's constant is 6.626 x 10^-34 Jos.)
A. 8.89 x 10^26 J
B. 5.09 x 10^14 J
C. 3.37 x 10^-19 J
D. 2.96 x 10^18 J
Answer:
C. 3.37 x 10^-19 J
Explanation:
Which is a property of all acids?
A. They increase the OH^- concentration in solution.
B. They contain OH^- ions.
C. They contain H3O^+ ions.
D. They increase the H^+ concentration in solution.
Acids increase the [tex]H^+[/tex] concentration in solution. Therefore, the correct option is D.
One of their essential characteristics is the ability of all acids to increase the concentration of H+ ions (protons) in a solution. Acids are chemicals that when dissolved in water add protons to the solution. As a result of this proton donation, the amount of [tex]H^+[/tex]ions in the solution increases, thereby lowering the pH. It is important to remember that not all acids contain[tex]H_3O^+[/tex] ions directly; Instead, [tex]H^+[/tex] ions can react with water molecules to generate [tex]H_3O^+[/tex] ions (hydronium ions).
Therefore, the correct option is D.
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Which of the following acids has a basicity of 2?
1 point
ethanoic acid
hydrochloric acid
nitric acid
sulphuric acid
Answer:
its answer is nitric acid...
this may help you...1234567890123345678901234567890
Answer:
1234567890123345678901234567890
Explanation:
trick question....
Nitrogen in plants and soil is changed into nitrogen compounds by _____ ?
Nitrogen Fixation because It's the process by which atmospheric nitrogen is converted either by a natural or an industrial means to form of nitrogen such as ammonia.
NO2 + H2O =
SO2 + H2O =
H2S + H2O=
SO2+ H2O=H2SO3
H2S+ H2O=H2SO4 +H2
NO2+ H2O= HNO3+NO
Give an example of each of the following chemical changes.
(a) A photochemical reaction involving
(i) silver salt
(ii) water
(b) A reaction involving
(i) blue solution
(ii) formation of dirty green precipitate
(c) Two gases combine to form white solid.
(d) A reaction where colour change is noticed.
Answer:
Give an example of each of the following chemical changes.
(a) A photochemical reaction involving
(i) silver salt
(ii) water
(b) A reaction involving
(i) blue solution
(ii) formation of dirty green precipitate
(c) Two gases combine to form white solid.
(d) A reaction where colour change is noticed.
Explanation:
a) A photochemical reaction involving silver salt is used in black and white photography.
AgCl breaks down and converts into Ag during this photochemical reaction.
(ii) Photochemicalreaction involving water takes place in plants during the photosynthesis process.
Plants prepare food(carbohydrate) by using sunlight water and CO2 gas.
(b) A reaction involving
(i) blue solution:
For example reaction of copper sulfate solution with an iron nail.
When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.
(ii) Reaction of ferrous sulfate with NaOH forms a dirty green precipitate of ferrous hydroxide.
(C) Two gases combine and form a white solid:
For example when HCl gas reacts with ammonia gas, then a white solid of ammonium chloride will be formed.
(d) A reaction where the color change is noticed.:
When an iron nail is placed in CuSO4 blue color solution, then it changes to green color and reddish-brown solid deposits at the bottom of the container.
The most outer solid portion of
the planet Earth
Answer:
The lithosphere is the most outer solid portion of
he most outer solid portion ofthe planet Earth.
crust is the outermost layer of earth.
Why is sodium an active metal
Answer:
Sodium is very reactive in nature. When exposed in air, it automatically forms Na2O. When it is put in water it reacts vigorously and starts burning on water. Due to the above reasons Sodium is called an active metal
Explanation: hope this helps pls mark as brainliest ty
why is dilute tetraoxosulphate(VI) acid not suitable for preparing carbon monooxide
Answer: Because this does not dissolve in water - it forms a barrier on the surface of the unreacted CaCO3 which prevents any further reaction. A small volume of CO2 is produced , but this stops after a short time . Conclusion: H2SO4 cannot be used with CaCO3 to produce CO2 gas .
Explanation:
What is meant by term valency? Explain it in terms of electrons donations and acceptance.
Answer:
Valency can be defined as a measure of the combining power of a chemical element with other atoms to form a molecule or chemical compound.
Explanation:
An atom can be defined as the smallest unit comprising of matter that forms all chemical elements. Thus, atoms are basically the building blocks of matters and as such determines or defines the structure of a chemical element.
Generally, atoms are typically made up of three distinct particles and these are protons, neutrons and electrons.
In Chemistry, electrons can be defined as subatomic particles that are negatively charged and as such has a magnitude of -1.
Valence electrons can be defined as the number of electrons present in the outermost shell of an atom. Valence electrons are used to determine whether an atom or group of elements found in a periodic table can bond with others. Thus, this property is typically used to determine the chemical properties of elements.
Valency can be defined as a measure of the combining power of a chemical element with other atoms to form a molecule or chemical compound.
Typically, valency is measured by the amount of hydrogen atoms that a chemical element can combine with or displace to form a molecule or chemical compound.
For example, Oxygen has a total number of eight (8) electrons while neon has total number of ten (10) electrons. Therefore, an atom of oxygen is able to gain (accept or receive) two (2) more electrons in order to have the same electron arrangements as the noble gas i.e an atom of neon with an atomic number of 10.
why doesn't calcium react with water in your body
explain pls
Answer:
Bones aren't made of calcium metal. Bones are a collegun structure filled in with mostly calcium carbonate and some calcium phosphate
Answer:
Bones aren't made of calcium metal. Bones are a collegun structure filled in with mostly calcium carbonate and some calcium phosphate
Explanation:
I hope this helps
Why phenol is more acidic than alcohol?
Answer:
Phenol is more acidic than cyclohexanol and acyclic alcohols because the phenoxide ion is more stable than the alkoxide ion. ... But in a phenoxide ion, the negative charge is delocalized over the benzene ring. Phenoxide ion is therefore resonance stabilized.
Answer:
Phenol is more acidic than cyclohexanol and acyclic alcohols because the phenoxide ion is more stable than the alkoxide ion. ... But in a phenoxide ion, the negative charge is delocalized over the benzene ring. Phenoxide ion is therefore resonance stabilized.
Explanation:
Please Mark me brainlist
please answer this as quickly as possible
Explanation:
I. Because an explosion is a very fast exothermic reaction
ll. it depends on the it's particle size
The values used in the scale of pH and pOH are derived from a system designed by ______.
Curie
Gordonsen
Dalton
Sorenson
KHP, the acid used in this experiment,
stands for potassium hydrogen
phosphorous.
True
False
Answer:
false
Explanation:
standard form is Potassium hydrogen phthalate
Which reaction will most likely take place based on the activity series? Li > K Ba CaNa > Mn > Zn > Cr> Fe> Cd Ni > H > Sb > Cu > Ag > Pd > Hg > Pt a. Ag+FeCl 3 b, Zn + CaO C. Ba+Na 2 CO 3 d . Cr+KNO3
Answer:
Among the given reactions,
a. Ag+FeCl 3
b, Zn + CaO
C. Ba+Na 2 CO 3
d . Cr+KNO3
which reaction is likely to take place based on the reactivity series?
Explanation:
The metal reactivity series is:
Li > K> Ba >Ca>Na > Mn > Zn > Cr> Fe> Cd Ni > H > Sb > Cu > Ag > Pd > Hg > Pt
The highly reactive metal will displace the less reactive metal from its compound during a displacement reaction.
a. Ag+FeCl 3
Ag is less reactive than Fe, so Ag cannot displace Fe from its compound.
This reaction also does not occur.
b, Zn + CaO
Zn is less reactive than Ca, so it cannot displace Ca from its compound.
This reaction does not occur.
C. Ba+Na 2 CO 3
Ba is more reactive than Na, so Ba displaces Na from its compound.
This reaction is possible.
d . Cr+KNO3
Cr is less reactive than K, so it cannot displace K from its compound.
Hence, This reaction is not possible.
Answer:
option c) Ba+Na 2 CO 3 -> BaCO3 +2Na
Answer:
C. Ba+Na 2 CO 3 -> BaCO3 +2NaA bird has flown 300 metres for 6 hours. What is the bird's speed? Formula for speed = d/t * 2 points
40 m/hr
50 m/s
50 m/h
50 m/min
Answer:
C
Explanation:
d=300
t=6hr
speed=?
speed=300/6
speed=50m/hr the important thing in this question is to get the right units
Please select the word from the list that best fits the definition
Occurs when an axon releases chemicals that allow a signal to jump across synapses between neurons
Answer:
When a nerve impulse reaches the end of an axon, the axon releases chemicals called neurotransmitters. Neurotransmitters travel across the synapse between the axon and the dendrite of the next neuron. Neurotransmitters bind to the membrane of the dendrite.Explanation:
I hope it's helpful for you ☺️State the name(s) of the sub-atomic particle(s) that have/has a positive charge. Answer with the name of the particle(s) only.
A. Neurons
B. Protons
C. Electrons
Answer:
protons because they have the most positive charge
The process of changing a gas to a liquid is known as _____.
sublimation
precipitation
evaporation
condensation
Answer:
Condensation is the process.
PLEASE HELP THIS IS AN EMERGENCY!!!!
A template of a Venn diagram representing common and differentiating characteristics of covalent and ionic bonds is shown.
Which of the following characteristics can be written only in space A? (5 points)
A.)Formed between atoms of similar electronegativities
B.)Formed between two metal atoms mostly found on the left of the periodic table
C.)Formed between two non-metal atoms mostly found on the right of the periodic table
D.)Formed between an atom that tends to lose electrons and an atom that tends to gain electrons
Answer:
D
Explanation:
Ionic bonds form when a metal and a nonmetal exchange electrons.
A) atoms with relatively similar electronegativities share electrons between them and form covalent bonds
B) the force that holds atoms together in a metallic substance is known as a metallic bond. such a solid consists of closely packed atoms....in short, the valence electrons in metals, unlike those of covalent bonds, are nonlocalized and capable of wandering relatively freely throughout the entire molecule
C) bonds formed between two nonmetals are mainly covalent bonds
.The characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.
Ionic bondIonic or electrovalent bonds are bonds formed between oppositely charged ions which are formed by a gain or loss of electrons and these ions are held together by strong electrostatic forces of attraction.
Properties of Ionic bondsThey are formed between oppositely charged ions ionsThey occur as a result of electrostatic forces of attraction between oppositely charged ions They are formed between an atom that tends to lose electrons {usually metals} and an atom that tends to gain electrons {usually non-metals}.Therefore, characteristic that can be written in A only is that ionic bonds are "formed between an atom that tends to lose electrons and an atom that tends to gain electrons" option D.
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