Answer: The number of protons are 34, number of neutrons are 43 and number of electrons are 36 in the given Se ion
Explanation:
The atom consists of 3 subatomic particles:
Protons: They are positively charged particles present in the nucleus of an atom.Electrons: They are negatively charged particles present in the orbits around the nucleus of an atom.Neutrons: They are neutral particles present in the nucleus of an atom.The mass number is the sum of the number of protons and number of neutrons in the nucleus of an atom. These are known as nucleons
The atomic number is defined as the number of electrons or number of protons present in an atom.
We are given:
A Se ion having mass number 77
Atomic number of Se = 34
Number of protons = 34
Number of neutrons = 77 - 34 = 43
Number of electrons = Atomic number - Charge
Charge = -2
Number of electrons = [34 - (-2)] = [34 + 2] = 36
Hence, the number of protons are 34, number of neutrons are 43 and number of electrons are 36 in the given Se ion
What causes hurricane on Saturn?
Hurricanes on Saturn are caused by when the water clouds heat up and rise, causing storms (not too sure if this is the right answer, hope it helped).
How many particles are in 54.5 g of aluminum? Show your work.
A. Convert the mass of aluminum to moles of aluminum. Molar mass of aluminum (Al) = 26.98 g/mol
B. Convert the moles of aluminum to particles of aluminum. There are 6.02 x 1023 particles/mol.
Why does platinum metal make a good catalytic surface for reactant molecules?
It causes reactant molecules to be less reactive.
It strengthens bonds between reactant molecules.
It prevents products from breaking away from the surface.
It holds reactant molecules in a good position for them to react.
Answer:
it holds reactant molecules in a good position for then to react
Answer:
D. It holds reactant molecules in a good position for them to react.
Explanation:
Got a 100 on e2020.
DIRECTION:Tell how charging takes place in each illustration.
Answer:
Due to static charges.
Explanation:
In the illustration, we can see that when we bring the magnet close to the body, the static charges present on the body rearrange theirselves and attracted by the magnet. The magnetic substance is responsible for the arrangement of charges on the body and when they are arranged, they attract each other so we can say that static charges are present on the body and rearrangement occurs in the body.
What is the frequency of an electromagnetic wave that has a wavelength of 8.5 x 10^2 m in a vacuum? (The speed of light in a vacuum is 3.00 x 10^8 m/s.)
A. 1.2 x 10^-3 Hz
B. 2.8 x 10^-6 Hz
C. 3.5 x 10^5 Hz
D. 2.6 x 10^11 Hz
Answer:
C=3.5 x 10^5 Hz
1234567890123345678901234567890
Answer:
1234567890123345678901234567890
Explanation:
trick question....
How many individual decay steps are in the decay chain of
uranium-238 before the stable end product of lead-206 is
produced?
Answer:
432
Explanation:
what are primary miniral nutrient in plant grawth
What volume of 12 M NaOH and 2 M NaOH should be mixed to get 2 litres of 9 M NaOH solution?
The volume of 12 M NaOH and 2 M NaOH should be mixed to get 2 litres of 9 M NaOH solution is 1.4 L and 0.6 L
What is Concentration ?
In chemistry, concentration is the abundance of a constituent divided by the total volume of a mixture.
Several types of mathematical description can be distinguished: mass concentration, molar concentration, number concentration, and volume concentration.
Amount of stuff = concentration x volume.
We can set up 2 equations:
V₁ = volume 12M NaOH.V₂ = volume 2M NaOH.(12×V₁) + (2×V₂) = 9×2 = 18
12V₁ + 2V₂ = 18 (1)
V₁ + V₂ = 2 (2)
From (2) we get:
V₁ = (2 − V₂)
Substituting V₁ back into (1) ⇒
12 (2−V₂) + 2V₂ = 18
24 − 12V₂ + 2V₂ = 18
10V₂ = 6
V₂ = 0.6L
From (2) we can say:
V₁ + 0.6 = 2
V₁ = 2 − 0.6 = 1.4L
Therefore, The volume of 12 M NaOH and 2 M NaOH should be mixed to get 2 litres of 9 M NaOH solution is 1.4 L and 0.6 L
Learn more about concentration here ;
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6. If more reactants are used in a chemical reaction, more products will be produced. This is
because a) More reactants cause the reaction to heat up
b) More reactants take up the same volume
c) More reactants have more atoms to react to form more products
d) Too many products can slow down the reaction
Answer:
D
Explanation:
What is the molarity of a solution prepared by adding enough water to 2 g of acetone to make a total volume of 1.60 l?
Explanation:
answer is in photo above
(20 points and excuse any offensive or seemingly bad language in this question) Budding and regeneration are two types of asexual reproduction.
Answer: true
Asexual reproduction is the process by which an organism is produced from a single parent cell. There are four major forms of asexual reproduction - budding, binary fission, regeneration and parthenogenesis. ... Regeneration is a type of asexual reproduction in which the organism is capable of regrowing certain body parts.
Explanation:
id k what u r talking abt but hope this helps
Which statement best describes John Dalton’s use of creativity in his work?
Answer:
c
Explanation:
When a substance melts, evaporates or boils, which four of the following things are true for it's particles?
Select four answers.
A. Lose energy
B. Gain energy
C. Move more
D. Move less
E. Become further apart
F. Become closer together
G. Overcome the attractive forces
H. The forces between them hold them more in place
Answer:
B, C, E, G
Explanation:
B - As particles are heated, they gain heat energy (or thermal energy, Q) from whatever the source may be.
C - Thermal energy particles gain is converted into kinetic, and the more KE/kinetic energy particles have, the more energy they have to move around.
E - When particles have more energy to move around more, they slide and move past each other and create more space; hence, they become further apart.
G - Eventually, particles will have enough energy and will move around so much that the attracting forces holding them together in the first place will be lesser than the particle's energy to break free and move from the attractive forces.
Please mark me as brianliest :D
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.
What is a covalent bond ?
What is a covalent bond ?
Answer is c A bond between two atoms resulting from a transfer of an electron.
Explanation:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
A covalent bonds is a bond between two atoms that is made up of share electrons.
Options B is correct.
TIMED PLS HELP AND WILL GIVE BRAINLIST
Given the following reaction:
2 Al + 2 KOH + 4 H2SO4 + 22 H2O --> 3 H2 + 2KAl(SO4)2•12H2O
If you start with 8.3 mL of 9.9M sulfuric acid, what is the theoretical yield of alum?
Answer:
19.4 g of alum, will be its theoretical yield
Explanation:
The reaction is:
2 Al + 2 KOH + 4 H₂SO₄ + 22H₂O → 3H₂ + 2KAl(SO₄)₂•12H₂O
Let's determine the amount of acid.
M are the moles contained in 1 L of solution or it can be mmoles that are contained in 1 mL of solution
M = mmol /mL
M . mL = mmol
We replace: 8.3 mL . 9.9 M = 82.17 mmoles
We convert to moles: 82.17 mmol . 1 mol / 1000mmol = 0.082 moles
Ratio is 4:2
4 moles of sulfuric acid can make 2 moles of alum
By the way, 0.082 moles of acid may produce ( 0.082 . 2) /4 = 0.041085 moles.
We convert moles to mass:
Molar mass of alum is: 473.52 g/mol.
0.041085 moles . 473.52 g/mol = 19.4 g
when water is added pH of the acidic solution
1 remain same
2 increases
3 decrease s
4 become zero
Answer:
the solution becomes less concentrated... meaning there is a decrease in acidity ...hence the pH slightly increases as lesser ph
means more acidity
Is the number of electrons in different shells of an atom fixed or unlimited ? Explain by giving an example.
Answer:
the number of electrons in a particular shell is given by the formula 2n^2 . However an electron when gets very exicited loose energy in the forms of radiation and comes in high energy level shell.
Cheese is an example of Solid in gas colloid Liquid in gas colloid Solid in liquid colloid Liquid in solid colloid
which chemical formula describes carbon monoxide?
a) CO
b) CO2
c) C100
d) CH4
Es(CO) .
muchas gracias!!
Answer:
[tex]{ \bf{a). \: CO}}[/tex]
A gas mixture contains 1.52 atm of Ne, 766 mmHg of He and Ar. What is the partial pressure, in atmospheres, of At if the gas mixture has a total pressure of 3.27atm
Answer:
0.74 atm.
Explanation:
From the question given above, the following data were obtained:
Pressure of Ne (Pₙₑ) = 1.52 atm
Pressure of He (Pₕₑ) = 766 mmHg
Total pressure (Pₜ) = 3.27 atm
Pressure of Ar (Pₐᵣ) =?
Next, we shall convert the pressure of He from mmHg to atm. This can be obtained as follow:
760 mmHg = 1 atm
Therefore,
766 mmHg = 766 mmHg × 1 atm / 760 mmHg
766 mmHg = 1.01 atm
Finally, we shall determine the partial pressure of Ar. This can be obtained as follow:
Pressure of Ne (Pₙₑ) = 1.52 atm
Pressure of He (Pₕₑ) = 1.01 atm
Total pressure (Pₜ) = 3.27 atm
Pressure of Ar (Pₐᵣ) =?
Pₜ = Pₙₑ + Pₕₑ + Pₐᵣ
3.27 = 1.52 + 1.01 + Pₐᵣ
3.27 = 2.53 + Pₐᵣ
Collect like terms
3.27 – 2.53 = Pₐᵣ
Pₐᵣ = 0.74 atm
Thus the partial pressure of Ar is 0.74 atm.
Which law states that the pressure and absolute temperature of a fixed quantity of gas are directly proportional under constant volume conditions?
Boyle’s law
Charles’s law
Dalton’s law
Gay-Lussac’s law
Answer:
Gay-Lussac’s law
Explanation:
Gay-Lussac’s law is one of the gas laws discovered and proposed by a French scientist called Joseph Gay Lussac (1778 - 1850). In this law, it is stated that the pressure (P) of a gas varies directly with the absolute temperature (T) at a constant volume.
That is;
: P ∝ T
: P/T = K
Where:
P = pressure exerted by the gas
T = absolute temperature of the gas
K = the constant.
Hence, according to this question, the law that states that "the pressure and absolute temperature of a fixed quantity of gas are directly proportional under constant volume conditions" is Gay-Lussac’s law.
Answer:
D. Gay-Lussac’s law
Explanation:
have a great day :)
1.1 Define the concept risky behaviour?
Answer:
Risky behavior or risk-taking behavior is defined according to Trimpop (1994) as “any consciously, or non-consciously controlled behavior with a perceived uncertainty about its outcome, and/or about its possible benefits, or costs for the physical, economic or psycho-social well-being of oneself or others.” In addition to this broad definition, there are other definitions of risky behavior depending on the field of research. While in the economic view, risk is defined in terms of the variability of possible monetary outcomes, in the clinical literature, the risk is generally defined as exposure to possible loss or harm (Schonberg, Fox, & Poldrack, 2011). Turner et al. (2004) described risk-taking behavior further as either a socially unacceptable volitional behavior with a potentially negative outcome in which precautions are not taken, such as speeding, drinking and driving, drugs abuse, unprotected sex and so on.
4 Calculate the mass of tin that can be extracted from 100 kg of tin ore that contains
1% tin by mass. Calculate the mass of waste produced.
Answer:
formula for calculating mass is
first U will HV to find number of moles
m=n×M
Which of the following are 'natural polymers
(bio-molecules)? Choose all that apply.
nylon
teflon
silk
cellulose
proteins
polyethylene
Answer:
cellulose
proteins
silk
Explanation:
A polymer is a macromolecule obtained by the combination of small molecules called monomers.
Polymers may be natural or synthetic. Natural polymers occur in nature. They may be part of living thing, and they include protein, cellulose and silk. These natural polymers are biological molecules.
Synthetic polymers are produced by industrial processes. Synthetic polymers include; nylon, Teflon and polyethylene.
¿QUE DATO DE LA CONFIGURACIÓN ELECTRÓNICA TE PERMITE UBICAR LOS ELEMENTOS QUÍMICOS EN LA TABLA PERIÓDICA?
The question is: WHAT DATA OF THE ELECTRONIC CONFIGURATION ALLOWS YOU TO LOCATE THE CHEMICAL ELEMENTS IN THE PERIODIC TABLE?
Explanation:
Elements which have same number of valence electrons tend to show similar chemical properties due to which they are placed in the same group.
Hence, electronic configuration of an element tells us the number of valence electrons present in an element. As a result, it becomes easy to locate the element in its respective group.
A flexible container has 5.00 L of nitrogen gas at 298 K. If the temperature is
increased to 333 K, what will be the new volume of that sample of nitrogen?
1) 0.179 L
2) 0.223 L
3) 4.47 L
4) 5.59
Answer: 5.59 L
Explanation: I'm pretty sure it's this. I just took this test and got it right. Hope this helps you out! :))
Answer:
5.59 L
Points earned on this question: 4
Explanation:
took the test
As the ZnCl2 dissolved, it separated into zinc ions and chloride ions. Choose the correct reaction.
A. Zinc was oxidized, chlorine was reduced.
B. Zinc was reduced, chlorine was oxidized.
C. This was not a redox reaction.
Answer:
This was not a redox reaction
Explanation:
A redox reaction is one in which a specie is oxidized and another specie is reduced. This means that one specie gains electrons while the other specie looses electrons.
Zinc chloride solid is composed of zinc ions and chloride ions. The ions only become free in solution. There is no change in the oxidation numbers of the ions as they dissolve in water.
Since the oxidation numbers of the species do not change, the process is not a redox reaction
State the optimum pH for sucrase activity and describe how sucrase activity changes at more acidic and more alkaline pH values.
Answer:
Explanation:
The rather high specific activity of intracellular sucrase towards sucrose is known to be optimal at pH 6.0 and at a temperature of about 30°C. And thus, we can say that the optimum pH for sucrase activity is exactly at 6. Also, it's behaviour is said to be decreasing with increasing acidic and increasing alkallinic values.