Answer:
D: a new substance
Explanation:
Chemical reaction
A change in matter that produces on or more new substances
Answer:
D. A new substance is always a result of a chemical reaction.
Explanation:
In a chemical reaction, one or more reactants reacts/decomposes to form one or more products.
50 points
Naturally occurring silver is composed of two isotopes: Ag-107 is 51.35% with a mass of 106.905092 amu, and the rest is Ag-109 with a mass of 108.9044757 amu. Calculate the average atomic mass of silver.
Answer:
I'm posting this so I can tell all of you that we should help him together in the comments because it seems we need more than one person to help him
Tungsten fits best into which category?
A. molecule
B. element
C. compound
D. mixture
Tungsten is an element. It is located in the d -block of periodic table. Thus it is a transition metal. Hence, option B is correct.
What is tungsten ?Tungsten is 74th element in periodic table. It is a transition metal thus, located in the d-block of periodic table. Tungsten has the chemical symbol W. Tungsten was first identified as an element in 1781.
The maximum melting temperature of any known element other than carbon, 3,422 °C, is reached by the unbound element, making its resistance all the more remarkable (which sublimes at atmospheric pressure). Tungsten has a boiling point of around 5930°C.
A few of the many alloys that contain tungsten and have many applications include radiation shielding, X-ray tubes, electrodes in gas tungsten arc welding, superalloys, and incandescent light bulb filaments.
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What volume would be occupied by 2.79 moles of nitrogen gas at STP?
Answer:
22.4
Explanation:
With a half-life of 28.8 years, how long will it take for 2000 mg of strontium-90 to decay to 125 mg? Response areaResponse areaResponse area years
Answer:
194
Explanation:
Step by step I just took the test
How many lone pairs of electrons should the nitrogen have?
Answer:
Nitrogen has one lone pair of electrons
Explanation:
The above two dots in picture are lone pair
18. How far does Larry move if traveling at 2m/s for 100s?
Answer:
200 m
Explanation:
Given data:
Speed of larry = 2 m/s
Time taken = 100 s
Distance travelled = ?
Solution:
Formula:
d = st
d = distance
s = speed
t = time
by putting values,
d = 2 m/s× 100 s
d = 200 m
The balanced equation below shows the products that are formed when butane (C4H10) is combusted.
2C4H10 + 1302 ——>8CO2 +10H20
What is the mole ratio of butane to carbon dioxide?
2:8
1:5
13:8
13.:10
Answer:
2:8
Explanation:
The reaction equation is a given as:
2C₄H₁₀ + 130₂ → 8CO₂ + 10H₂O
From the reaction equation, the mole ratio is 2:8
Butane is C₄H₁₀
Carbon dioxide CO₂
From the reaction;
2 moles of butane will produce 8 moles of carbon dioxide
Answer:
A) 2:8
Explanation:
Took the quiz and was right
what is the smallest atomic radius
Answer:
Helium
Explanation:
Helium has the smallest atomic radius. This is due to trends in the periodic table, and the effective nuclear charge that holds the valence electrons close to the nucleus.
what type of reaction occurs between sodium and calcium fluoride
Scientific Notation and Significant Figures Problem:
Answer:
84130.44698 and 8.413044698*10^4
Explanation:
The __ increases by 1 as you go left to right across the periodic table.
A. Atomic mass
B. Atomic number
C. Number of neutrons
D. Number of ions
The __ increases by 1 as you go left to right across the periodic table.
A. Atomic mass
B. Atomic number
C. Number of neutrons
D. Number of ions
Answer C
What are 3 atoms that have 6 energy levels?
What Elements that have an atomic number less than 37 and atomic mass greater than 78.4u?
Answer:
krypton
bromine
selenium
What group of elements is commonly used in jewelry and construction?
a. Alkali Metals b. Halogens .c.Noble gases d. Transition metals
Answer:
A. Alkaline Metals
Explanation:
I majored in Chemistry
How much will a student earns in 19 weeks if she works for 5 hours each week at a rate of $7 / hour?
Answer:
665
Explanatio
Answer:
$665
Explanation:
5 hours per week × $7 per hour = $35 per week
$35 per week × 19 weeks = $665
Why do you think Leeuwenhoek was so excited about what he saw?
Answer:
van Leeuwenhoek called the organisms he saw in his microscope "animalcules." also he shined light on specimen so that he could see the right cells
1. How much heat does 23.0 g of water absorb as its temperature increases from 25.4 °C to 42.8 °C?
2. A sample of unknown metal has a mass of 120.7 g. As the sample cools from 90.5 °C to 25.7 °C, it releases 7020 J of energy. What is the specific heat of the sample?
Answer:
Q = 1672.84 j
c = 0.898 J/g.°C
Explanation:
1) Given data:
Mass of water = 23.0 g
Initial temperature = 25.4°C
Final temperature = 42.8° C
Heat absorbed = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.18 J/g°C
ΔT = 42.8°C - 25.4°C
ΔT = 17.4°C
Q = 23.0 g × × 4.18 J/g°C × 17.4°C
Q = 1672.84 j
2) Given data:
Mass of metal = 120.7 g
Initial temperature = 90.5°C
Final temperature = 25.7 ° C
Heat released = 7020 J
Specific heat capacity of metal = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.7°C - 90.5°C
ΔT = -64.8°C
7020 J = 120.7 g × c × -64.8°C (Negative sign shows heat is released)
7020 J = 7821.36 g.°C × c
c = 7020 J / 7821.36 g.°C
c = 0.898 J/g.°C
What is the standard deviation of this data set?
{73, 70, 80, 12, 98, 27}
A.
123.8
B.
33.2
C.
30.3
D.
28.0
To solve this we must be knowing each and every concept related to standard deviation. Therefore, 30.3 is the standard deviation of this data set. The correct option is option C.
What is standard deviation?In descriptive statistics, the standard deviation measures how widely the data points vary from the mean. It describes how values are distributed throughout the information sample and calculates how widely apart data points are from the mean.
Mathematically,
73+70+80+12+98+27 =360
mean of observations = 360/6=60
deviations from the mean
(73−60), (70−60), (80−60), (12−60), (98−60), (27 −60)=13, 10, 20, -48, 38, -33
standard deviation (σ) formula can be given as
σ=√(13)²+(10)²+(20)²+(-48)²+(38)²+(-33)²/6
On calculations, we get:
σ=30.3
Therefore, 30.3 is the standard deviation of this data set. The correct option is option C.
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How many grams of K2SO4 are in:
Answer:
174.2 grams
Explanation:
This compound is also known as Potassium Sulfate.
The SI base unit for amount of substance is the mole.
1 mole is equal to 1 moles K2SO4, or 174.25 grams.
Who can help me please ? Yes I will give BRAINLIST . And yes this is 6th grade work . Please help me ( it’s science btw )
Answer:
true and b are the answers I think
Answer:
true/precipitation
Explanation:
How many moles of gas would there be given 29.90 liters, 336.99 mmHg and 390K?
Moles of gas : 0.414
Further explanationGiven
V =29.90 liters,
P = 336.99 mmHg = 0,443 atm
T = 390K
Required
moles
Solution
In general, the gas equation can be written
[tex]\large {\boxed {\bold {PV = nRT}}}[/tex]
where
P = pressure, atm , N/m²
V = volume, liter
n = number of moles
R = gas constant = 0.082 l.atm / mol K (P= atm, v= liter),or 8,314 J/mol K (P=Pa or N/m2, v= m³)
T = temperature, Kelvin
Input the equation
n = PV/RT
n = 0.443.29.9/0.082.390
n= 0.414 moles
model and Schrodinger's atom model?
Explanation:
the model assumes that the electron is a wave and tries to describe the regions in space orb orbitals where most likely to be found
16.
Magnesium reacts with hydrochloric acid according to the equation below.
Magnesium bertindak balas dengan asid hidroklorik mengikut persamaan berikut.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
What is the volume of hydrogen gas produced at room condition if 0.6 g of
magnesium is added to the excess of sulphuric acid?
[Relative atomic mass : Mg = 24 : molar volume = 24 dmº mol' at room condition]
Berapakah isipadu gas hidrogen yang dihasilkan pada keadaan bilik jika 0.6 g
magnesium ditambahkan kepada asid hidroklorik berlebihan."
[Jisim atom relative:Mg = 24 : isipadu molar = 24 dm mol! pada keadaan bilik]
A 0.6 cm
B 6.0 cm
C 60.0 cm
D 600 cm
What is the charge of an atom with 21 protons and 20 electrons?
What is the percent composition of C3H8?
Answer: Hydrogen - 18.286%( mass present)
Carbon - 81.714%(mass present)
Explanation:
Mass percentage does not have any unit as numerator and denominator contains the same unit. Therefore, the percent composition of C and H in C[tex]_3[/tex]H[tex]_8[/tex] is 81.8% and 18% respectively.
What is percentage by mass?Mass percentage represents the the percentage of each element that is making a particular compound.
Mathematically,
Percentage of mass = (component’s mass ÷ total mass) x 100%
Atomic weight of different element of calcium phosphate
C= 12g/mol , H=1g/mol
Total mass of Carbon element in C[tex]_3[/tex]H[tex]_8[/tex] = 12 × 3 = 36
Total mass of hydrogen atom in C[tex]_3[/tex]H[tex]_8[/tex] = 1 × 8 = 8
Total molar mass of C[tex]_3[/tex]H[tex]_8[/tex] =36 + 8 =44 g/mole
Percentage of carbon in C[tex]_3[/tex]H[tex]_8[/tex] =36/44× 100 =81.8%
Percentage of hydrogen in C[tex]_3[/tex]H[tex]_8[/tex] =(8÷44)×=18%
Therefore, the percent composition of C and H in C[tex]_3[/tex]H[tex]_8[/tex] is 81.8% and 18% respectively.
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HELPPPPPPP
DETERMINE THE CHARGE OF ELECTRON CLOUD OF POTASSIUM
Answer:
+1
Explanation:
A Potassium atom is represented with the sign "K" in chemistry and have atomic number 19.
The charge of electrons causes a matter to experience a force and it can be positive or negative.
In Potassium atom, the electric charge is +1 to enter a stable electron configuration as there is only one valence electron in the outermost shell of potassium atom. As potassium atom will lose electron it will become positively charged.
Hence, the correct answer is "+1".
Using the phase diagram for CO2, what phase is carbon dioxide in at 20°C
and 25 atm pressure?
A. It is at its melting point.
B. It is at its boiling point.
C. It is in the gas phase.
D. It is in the liquid phase.
Answer:
since the temperature is approximate to room temperature at a small pressure of 25atm, carbon dioxide is in gas phase.
Answer:
Explanation:
C. It is in the gas phase.
who else just copy and pastes the questions from edge?
Answer:
haha
Explanation:
yea because my phat a22 is to lazy
which of the two metal ions mg2+ and zn2+ is the most reactive why?
Answer:
Mg2+
Explanation:
The most reactive ions from the given choices is the magnesium ion. This is because it is higher in the activity series of metals.
Zinc ion is below this specie in the activity series.
As a rule, ions above another on the activity series are generally more reactive than those below.
From any solution, magnesium ion will displace the zinc ion in such process.
The position of metallic ions determines their reactivity.
cual es el simbolo quimico que tiene 55 protones ?
Answer:
The answer for this question is Cs
