Answer:
B)As you go from left to right, reactivity of metals increases. As you go down in a group, reactivity of metals decreases.
Explanation:
reactivity of metals can be explained as how it can easily lose electron, i.e oxidize as well as reaction with non-metals.
There are factors that influence the reactivity of metals such as
1)atomic radius
2)nuclear charge
3)shielding effect
4) The sublevel arrangement of electrons
In the periodic table,the group 1, known as alkali metals, are the most reactive metals
Therefore, as we from left to right, reactivity of metals increases. As we move down in a group, reactivity of metals decreases.
The density of aluminum is 2.7 g/cm3. What is the density in kilograms per liter? Use appropriate sig figs and no unit
Answer:
2.7 kg/L
Explanation:
Step 1: Given data
Density of aluminum (d): 2.7 g/cm³
Step 2: Convert "d" for g/cm³ to kg/cm³
We will use the conversion factor 1 kg = 10³ g.
2.7 g/cm³ × (1 kg / 10³ g) = 2.7 × 10⁻³ kg/cm³
Step 3: Convert "d" from kg/cm³ to kg/L
We will use the conversion factor 1 L = 10³ cm³.
2.7 × 10⁻³ kg/cm³ × (10³ cm³/ 1 L) = 2.7 kg/L
9.87 x 10^-5km - 8.76 x 10^-6km
If I mix 10 grams of baking soda with 15 grams of vinegar, what should the mass
of the water and carbon dioxide gas be when added together?
Answer:
25 grams
Explanation:
10 +15 =25 you welcome
A woman is brought into the emergency room experiencing nausea and vomiting. She is also hyperventilating. She says that she ingested a bottle of aspirin about two hours earlier. Aspirin (acetylsalicylic acid) is converted to salicylic acid in the stomach. Assuming 100% conversion to salicylic acid.
Required:
Calculate the percentage of protonated and unprotonated forms of salicylic acid in her stomach, given a pH of 2.0 for the stomach.
Answer:
Protonated form: 96.87%
Unprotonated form: 3.13%
Explanation:
To find the percentage of protoned and unprotoned forms of salicylic acid we must use Henderson-Hasselbalch equation:
pH = pKa + log [A⁻] / [HA]
Where pKa of salicylic acid is 3.49; [A⁻] is the unprotonated form and [HA]:
2.0 = 3.49 + log [A⁻] / [HA]
0.03236 = [A⁻] / [HA] (1)
And as:
[A⁻] + [HA] = 100% (2)
Replacing (2) in (1):
0.03236 = 100 - [HA] / [HA]
0.03236 [HA] = 100 - [HA]
1.03236[HA] = 100
[HA] = 96.87%And [A⁻]:
[A⁻] = 100 - 96.87
[A⁻] = 3.13%
How does rainfall affect a biome !?!?!!??!
metalloids tend to be
Answer:
Metalloids tend to be shiny like metals but brittle like nonmetals. Because they are brittle, they may chip like glass or crumble to a powder if struck. Other physical properties of metalloids are more variable, including their boiling and melting points, although all metalloids exist as solids at room temperature.
Explanation:
If 2 g of element X combines with 7 g of element Y to form compound XY, how many grams of Y
are needed to form compound XY2?
(1 Point)
Answer:
14g of Y to form the compound XY₂
Explanation:
In the compound XY, you have 1 mole of X and 1 mole of Y. Thus, you can imagine the molar mass of X is 2g/mol and molar mass of Y is 7g/mol.
Now, in the compound XY₂, you have 1 mole of X but 2 moles of Y.
If you have 2g of X, in this case you will need:
2 moles Y * (7g / mol) =
14g of Y to form the compound XY₂
The amount of element Y needed to form compound XY2 is; 14g of element Y.
From the law of conservation of mass which states that;
Matter can never be created nor destroyed.
By stoichiometry;
Since:
7 g of element Y to form compound XY(y =1)
a g of element Y to form compound XY2(y =2)
In essence,
a g = (2 × 7g)/1
a = 14g
Therefore, 14g of element Y is needed to form compound XY2.
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The elementary gas-phase reaction
A → B
takes place isobarically and isothermally in a PFR where 63.2% conversion is achieved. The feed is pure A. It is proposed to put a CSTR of equal volume upstream of the PFR. Based on the entering molar flow rate to A to the first reactor, what will be the intermediate from the CSTR, X1, and exit conversion from the PFR, X2, based on the feed to first reactor?
Answer:
Xa1 = 0.5
Xa2 = 0.815
Explanation:
Elementary gas-phase reaction
A → B taking place isobarically and isothermally and the feed is Pure
conversion rate = 63.2%
The intermediate from the CSTR (XA1 ) = 50%
conversion in the PFR at the exit ( XA2 ) = 0.815
Attached below is the detailed
is the solid planet itself.
Which material is typically used as a thermal insulator
Answer: plastic, wood, rubber
Explanation:
Answer:
Lots of items.
Explanation:
Fiber, mineral wool, and corks.
Please help ASAP! Will mark as brainliest
Answer:
You're right Transition Metal
The concentration of two reactants is decreased by the same amount. How
will this change in concentration affect the reaction?
A. The reaction rate will increase by the same amount the concentrations were increased
B. The change in concentration will affect the rate of the reaction according to the rate law
C. The change in the reaction rate depends on the balanced chemical equation
D. The reaction rate will decrease by the same amount the concentrations were decreased
The emission spectrums are known for the elements below. Line spectra for boron, lithium, hydrogen, helium, potassium and unknown sample. Boron has 3 purple lines, 1 blue line, 2 blue-green lines and 2 orange lines. Lithium has 2 purple lines, 2 blue lines, 2 blue-green lines, 1 orange line and 1 red line. hydrogen has one line of each purple, blue, blue-green and red. helium has 3 purple lines, 3 blue lines, 3 blue-green lines 1 yellow line and 2 red lines. Potassium has 8 purple lines, 6 blue-green lines, 10 green lines, 3 yellow lines, 2 orange lines and 6 red lines. The unknown sample has Potassium has 8 purple lines, 6 blue-green lines, 10 green lines, 3 yellow lines, 2 orange lines and 6 red lines. What elements are in the unknown sample? Check all that apply. boron lithium hydrogen helium potassium
Answer:
The Answer is (B) lithium and (E) potassium
The elements are in the unknown sample of emission spectrums is lithium and potassium. correct options are B and E.
What is emission spectrums?The emission spectrum of elements are is a formation of different types of lines of different colors and are of different wavelengths when their is emission of the light through a chemical substance is known to be emission spectrums.
The line of red color have the longest wavelength and can be measured easily with the help of spectrophotometer during the emission of light passing through it.
Therefore, elements are in the unknown sample of emission spectrums is lithium and potassium. correct options are B and E.
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9. To become like a noble gas the element P will have a charge of
Answer:
to become a noble gas element P will have 2 electrons in it's outer most energy level if it has one energy level
and eight in the last energy level if more than one
Q1) A vapor-compression refrigeration system operates on the cycle of Fig. 9.1. The refrigerant is 1,1,1,2-Tetrafluoroethane. Given that the evaporation T = 4°C, the condensation T = 34°C, η(compressor) = 0.76, and the refrigeration rate = 1200 kJ⋅s−1, determine the circulation rate of the refrigerant, the heat-transfer rate in the condenser, the power requirement, the coefficient of performance of the cycle, and the coefficient of performance of a Carnot refrigeration cycle operating
between the same temperature levels.
Answer:
i) 0.5071 (kg/s)
ii) -1407.1 kj/kg
iii) 204.05 Kw
iv) 5.881
v) 9.238
Explanation:
Given Data:
evaporation temperature ( T ) = 4°c = 277.15 K
Condensation Temperature ( T ) = 34°c = 307.15 K
n ( compressor efficiency ) = 0.76
refrigeration rate = 1200 kJ.s^-1
i) determine the circulation rate of the refrigerant
m = [tex]\frac{Q}{H2 - H1}[/tex] = [tex]\frac{Q}{H2 - H4\\}[/tex] ------- 1
Q = 1200 Kj.s^-1
H2 = entropy at step 2 = 2508.9 (kJ / kg ) ( gotten from Table F )
H4 = entropy at step 4 = 142.4 ( kJ/ kg )
back to equation 1
m ( circulation rate of refrigerant ) = 0.5071 (kg/s)
ii) heat transfer rate in the condenser
Q = m ( H4 - H3 )
= 0.5071 ( 142.4 - 2911.27 )
= -1407.1 kj/kg
where H3 = H2 + ΔH23 = 2911.27 (kj/kg) ( as calculated )
iii) power requirement
w = m * ΔH23
= 0.5071 (kg/s) * 402.37 (kj/kg) = 204.05 Kw
where: ΔH23 = [tex]\frac{H'3 - H2 }{0.76}[/tex] = [tex]\frac{2814.7-2508.9}{0.76}[/tex] = 402.37 (kj/kg)
iv) coefficient of performance of a cycle
W = Qc / w
= 1200 Kj.s^-1/ 204.05 kw
= 5.881
v) coefficient of performance of a Carnot refrigeration cycle
[tex]w_{carnot} = \frac{T2}{T4 - T2}[/tex]
= 277.15 / ( 307.15 - 277.15 )
= 9.238
if the atomic number of Potassium is 19 and its mass is 39 what will be the number of electrons protons and neutrons and atoms also give its symbol and sure its electronic configuration pictorially
Answer:
Explanation:
Symbol: K
Protons = 19
Electrons in an atom: 19
Neutrons: 39 - 19 = 20
Draw the nucleus at the center. Label it with 19 Protons and 20 Neutrons.
Draw a circle around the nucleus.
Put two dots opposite each other on the circle's circumference.
Draw another circle with its center at the nucleus bigger than you first circle.
Space 8 electrons around the circumference.
Draw a third circle like the other 2 only bigger.
Space 8 electrons around this circle's circumference.
Draw 1 more circle bigger than the third circle.
It has 1 electron.
What is the atomic mass of the element in period 5, group 13?
Answer:
You would be looking at indium, Which is 114.818
Explanation:
Which of the following molecules would contain a polar covalent bond? A molecule containing two atoms
Answer:
of different elements with different electronegativities
Explanation:
A molecule containing two atoms "of different elements with different electronegativities"
A polar covalent bond exists when two different atoms (non-metals) with different electronegativities are able to share their electrons in a covalent bond.
Some examples of polar covalent bonds are seen in:
1. Ammonia(NH3): The polar covalent bonds exists between the nitrogen and hydrogen atoms.
2. Water(H2O): The polar covalent bond exists between hydrogen and oxygen. The oxygen molecule has a net negative charge while the hydrogen atoms have a net positive charge.
15. Glucose reacts with oxygen to give CO2 and H20. What mass of oxygen (in grams) is required for
complete reaction of 25.0 g of glucose?
a. 25.0 g
b. 0.83 g
c. 26.6 g
d. 30.1 g
How do plants differ from the desert to those that live in the tundra !?!?!?!?!
Answer:
In the desert, the climate is hot and dry, while in the tundra, it is cold and wet.
Explanation:
in the desert, plants need more water, while in the tundra, they have ice and snow
Which of the following characteristics of the pineal gland is not correct? A. The pineal gland is located in the brain, above the cerebellum. B. The pineal gland acts as an internal clock. C. The pineal gland regulates sleep and waking cycles. D. The pineal gland regulates salt and water levels.
Answer:
D
Explanation:
The pineal gland regulates salt and water levels.
The pineal gland does not regulate salt and water levels. Therefore, option (D) is correct.
What is the pineal gland?The pineal gland can be described as a pinecone-shaped small gland located in the middle of the human brain. The pineal gland is the main site for melatonin secretion, which regulates the internal clock of the body.
The dimensions of the pineal gland can be described as about 0.3 inches long and weighing 0.1 grams. The pineal gland is made of pinealocytes and supporting cells that are similar to the astrocytes in the brain.
The pineal gland secretes the hormone melatonin and this hormone regulates the circadian rhythm of the body and also reproductive hormones. The secretion of hormones depends upon the quantity of light a person is exposed to.
This hormone is formed in huge amounts when it is dark. The presence of light prevents the secretion of melatonin which controls circadian rhythms.
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How is Belle viewed?
In beauty and the beast
(Ignore the subject)
Answer:
She is viewed differently by different people. Of course the beast is in love with her. Gaston is in love with her as well but in a more objectifying way. Her village thinks she's odd and different, and her Belle is her father's hero.
Explanation:
In 1909, Ernest Rutherford performed an experiment to explore the atomic structure. In his experiment, he projected high-speed α particles onto a thin gold foil. He found that all α particles did not follow the same path. Most of the particles passed through the foil without any scattering, implying that most of the space in an atom is empty. Some particles were scattered at a large angle, and very few of them scattered back in the direction from which they had come. Based on these observations, Rutherford proposed an atomic model, which is known as Rutherford’s atom.
On the basis of Ruthertord's experimentel observations, which of the following statements describes the structure of the atom according to Rutherford's atomic model?
A. In an aborn, negatively charged electrons are dispersed in the space surrounding tho positively charged nucleus of an atom
B. ln an atom, au of the positive and negative charges are randomly distributed.
C. In an atom, the postive eherges are ocated in a smal core wrin the atom cated the nucleus
D. In an atom, positively charged porticles are dispersed in the space surounding the negiively charged sphere
Answer:
A. In an aborn, negatively charged electrons are dispersed in the space surrounding tho positively charged nucleus of an atom
C. In an atom, the positive energies are located in a small core within the atom called the nucleus
Explanation:
the answers are options A and C.
In the year 1909, Emest Rutherfords performed this experiment from which his atomic model came about. The atomic model gave a description of atom to be a small core which is dense and which has a nucleus that is positively charged. Rutherford in his model tries to give a description of the atom as mainly just empty space and that it has electrons going through a static or fixed charged nucleus. While doing this they are in sets and their paths are predictable.
what kind of energy is stored when you compress a seat cushion?
Answer:
chemical energy tell me if i right
Answer: Elastic potential energy
Explanation:
Explain how balanced and unbalanced forces affect an object's motion differently.
What body system controls the brain, spinal cord, nerves, and sense organs?
Answer:
The central nervous system
All elements in the same group (Column) on a periodic table have what in common?
Who’s the hottest sway boy?
A. Noah beck
B. Bryce hall
C. Josh Richards
D. Blake gray
Answer:
E: None of the Above
Explanation:
2 NaHCO3(s) ⇔ Na2CO3 (s) + H2O(g) + CO2(g) enthalpy = +128 kJ is at equilibrium. What happens to [CO2] when the H2O is added?
The question is incomplete; the complete quqestion is ;
iv. What happens to [CO2] when the H2O is added?
a. increased
b. decreased
c. no change
Answer:
decreased
Explanation:
Recall that the reaction shown in the question is endothermic (positive change in enthalpy).
When water is added to the system, carbonic acid is formed as follows;
CO2(g) + H2O(l) ---> H2CO3(aq)
This reaction is decreases the concentration of the carbon IV oxide as it dissolves in the water.
The electromagnetic wave relationship that has the formula c = ν times λ; What does each letter or symbol mean?
Answer:
c is speed of light (in terms of velocity)
v is velocity
lambda is wavelength
Explanation:
speed of light is constant at 3 x 10^8 m/s which is a velocity value. Lambda is usually in the units of nanometers which represents wavelength.