Answer:
I would say a dense cloud of interstellar gas and dust.
When copper is bombarded with high-energy electrons, X rays are emitted. Calculate the energy (in joules) associated with the photons if the wavelength of the X rays is 0.154 nm.
Answer:
E = 12.92 × 10^(-16) J
Explanation:
Formula for energy is;
E = hc/λ
Where;
h is Planck's constant = 6.63 x 10^(-34) J.s
c is speed of light = 3 × 10^(8) m/s
λ is wavelength = 0.154 nm = 0.154 × 10^(-9) m
E = (6.63 x 10^(-34) × 3 × 10^(8))/(0.154 × 10^(-9))
E = 12.92 × 10^(-16) J
The energy associated with the photons of X rays with a wavelength of 0.154 nm is 1.29 × 10⁻¹⁵ J.
When copper is bombarded with high-energy electrons, X rays, with a wavelength of 0.154 nm (λ) are emitted.
We can calculate the energy (E) associated with the photons of these X rays using the Planck-Einstein relation.
[tex]E = \frac{h \times c }{\lambda } = \frac{(6.63 \times 10^{-34}J.s ) \times (3.00 \times 10^{8}m/s ) }{0.154 \times 10^{-9} m } ]= 1.29 \times 10^{-15} J[/tex]
where,
h: Planck's constantc: speed of lightThe energy associated with the photons of X rays with a wavelength of 0.154 nm is 1.29 × 10⁻¹⁵ J.
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define atom and give an example
Answer:
Many atoms consist of a positively charged nucleus composed of protons and neutrons surrounded by a negatively charged cloud of electrons. At its most basic level, an atom is any particle of matter that contains at least one proton. ... Here are some examples of atoms: Neon (Ne) Hydrogen (H)
Explanation:
HELP QUICK What is the mass of an object that has a volume of 2 ml and a density of 10g/ml?
Answer:
The answer is 20 gExplanation:
The mass of a substance when given the density and volume can be found by using the formula
mass = Density × volumeFrom the question we have
mass = 10 × 2
We have the final answer as
20 gHope this helps you
What is a stable electron configuration?
Which of the following is the least likely to remain homogeneous?
. O A. All of these
O B. A supersaturated solution
O C. An unsaturated solution
O D. A saturated solution
Answer:
all
of them
Explanation:
3. describe how unequal heating causes weather
Answer:
The uneven heating causes temperature differences, which in turn cause air currents (wind) to develop, which then move heat from where there is more heat (higher temperatures) to where there is less heat (lower temperatures).
Explanation:
How many cesium atoms are in 21.9 grams?
In the apple activity you completed which of the following is an example of a constant
Answer: the type of apple because it is an example of a constant
Explanation:
Please help me with this I’ve been on this question for 10 minutes now...
Answer:
A
Explanation:
we know that pangea was when all the continents were connected and the tectonic plates moved, causing pangea to split into multiple pieces. so north america was formed by moving tectonic plates.
i hope this helps :))
(True or False) Only an odd number of orbitals is possible for any electron sublevel?
Answer:
The statement is true
I found this doing research.
Apparantly, each sub level is made up of one or more orbitals and the orbitals in each sub level are always odd number. Each orbital can only have two electrons and those two electrons will have opposite spin.
Explanation:
Answer:
True
Explanation:
For lunch you have a glass of sweetened ice tea. The glass contains crushed tea leaves, sugar, a slice of lemon, and both liquid and frozen water (ice cubes). Which of the following categories of matter best describes the contents of the glass? *
Answer:
I think solids
Explanation:
sorry if its not right
Are hemoglobin formation and functioning brains and muscles benefits of Iron?
Line M passes through the points (-5, 9) and (-1,9).
12
10-
8
6
2
-12-10-8-6-4-22
2
6 8 10 12 X
6
-10
-12-
Which is true of line M?
Answer:
line m is vertical line with an undefined slopel line correct answer is 6 8 10 12 x
If a substance has a density GREATER
than the liquid it's in, then it will
Answer:
sink
Explanation:
a substance with a higher density than others will sink and vice versa
One of the uses of methanol (CH3OH) in dilute form is as a windshield washer antifreeze. In pure form, methanol has a molar concentration of 24.7M. How many moles are contained in 500 mL of solution?
Mole itself is the number of particles contained in a substance
1 mole = 6.02.10²³ particles
Mole : the ratio of the amount of substance mass and its molar mass
[tex]\large{\boxed{\boxed{\bold{mole=\frac{mass}{molar\:mass}}}}[/tex]
Molarity is a way to express the concentration of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
Molar concentration of methanol=24.7 M
Volume of solution = 500 ml = 0.5 L
[tex]\tt mol=M\times V\\\\mol=24.7\times 0.5\\\\mol=12.35[/tex]
6.82
A 2.10-mole sample of crystalline acetic acid, ini-
tially at 17.0°C, is allowed to melt at 17.0°C and is
then heated to 118.1°C (its normal boiling point) at
1.00 atm. The sample is allowed to vaporize at.
118.1°C and is then rapidly quenched to 17.0°C, so
that it recrystallizes. Calculate AH° for the total pro-
cess as described.
Answer:
0 kj
Explanation:
melting/initial temperature = 17.0°c
boiling point = 118.1°C
pressure = 1.00 atm
2.10 mole sample of crystalline
attached below is the detailed solution required
How many atoms are in a sample of 2.89 moles of potassium (K)?
Answer:
The answer is
1.74 × 10²⁴ potassium atomsExplanation:
To find the number of atoms given the number of moles we use the formula
N = n × Lwhere n is the number of moles
N is the number of entities
L is the Avogadro's constant which is
6.02 × 10²³ entities
From the question
n = 2.89 moles
We have
N = 6.02 × 10²³ × 2.89
We have the final answer as
1.74 × 10²⁴ potassium atomsHope this helps you
As part of a chemistry experiment, Sam notes that the temperature at which liquid mercury
freezes into a solid is -102 Fahrenheit (F). The beaker of liquid mercury provided to him Is
at a room temperature of 68". By how many degrees will Sam have to cool the liquid
mercury for it to freeze into a solid?
-102"F
-34°F
102°F
170°F
o
Answer:
-34¨F
Explanation:
Ben makes five paper helicopters with different wing lengths. He drops them the same way from a height of two meters for five trials each. He records the amount of time it takes for each helicopter to fall to the ground. What is the independent variable?
Answer:
Wing length
Explanation:
According to the given excerpt, independent variable is 'wing length' and dependent variable is 'amount of time it takes for helicopter to hit the floor'.
Independent variable refers to the variable that do not undergo any change or shift in the course of the experiment of research. The other variables are measured using the constant independent variable. The value obtained from the independent variable is independent. On the other and, the dependent variable witnesses change with respect to the independent variable.
Matter is anything that takes up space and can be described by physical and chemical properties. Which statement
BEST differentiates chemical properties from physical properties?
A)
Physical properties are properties that can be physically seen or touched,
while chemical properties can only be found when matter is mixed with
specific chemicals.
B)
Physical properties are measured when matter changes its physical state,
while chemical properties can only be measured if matter remains in one
state for an extended time.
C)
Physical properties are difficult to measure because they require special
tools to detect, and chemical properties are easy to measure and require
not special tools to detect.
D)
Physical properties can be measured/observed without changing matter
into something else, while chemical properties describe matter's ability to
react/combine with other matter.
Answer:
D)
Physical properties can be measured/observed without changing matter
into something else, while chemical properties describe matter's ability to
react/combine with other matter.
Explanation:
Physical Change
The changes that occur only due to change in shape or physical properties but their chemical or internal composition remain unchanged.
1 = These changes were reversible.
2= They have same chemical property.
3= These changes can be observed with naked eye.
Example :
Water converting to Ice
Water converting to gas
In this water molecule remain the same only they rearrange themselves that change its state of mater not composition
Chemical change:
The changes, that occur due to change in the composition of a substance and result in a different compound is known as chemical change.
1 = These changes are irreversible
2 = These changes occur due to chemical reactions
3 = These may not be observed with naked eye
Example:
Combustion of fuel or wood: that oil or wood convert into energy, CO₂ and ash in case of wood
Boiling of egg: that change the chemical composition of protein in the egg .
The reaction of Hydrogen and oxygen:
H₂ (g) + O₂ (g) → 2H₂O (l)
How many atoms of aluminum are in a molecule of magnesium aluminum oxide (Al2MgO4)?
Answer:
12
Explanation:
A + ion (positive ion, one with extra positive charge)?
Answer:
If an ion has a positive charge then it has lost an electrons.
Explanation:
So you don't "gain" anything when the ion has a positive charge. It loses an electron which means it has more protons than electrons. Thus, the ion has a positive charge. If it "gained" an electron then it would have a negative charge.
HELP PLEASEE
Name three elements present in the ingredients of the cereal drink which are not listed in the nutrition facts
Answer:
Let's start with the fact that cereals , are made of grains and are mostly carbohydrates. therefore they contain carbon oxygen and hydrogen. They also contain proteins so have nitrogen. Plants have the minerals that are in the soil where they grow, so the list you have is correct. They also generally have added vitamins ad minerals. The vitamins contain C, H, O N, and a few others such as sulfur, The added minerals might contain:copper, iron, zinc, cobalt, selenium, silicon and molybdenum .
Mark me as brainliest if it was helpful
The three elements present in the ingredients of the cereal drink which are not listed in the nutrition facts are Iron, Calcium, and Zinc
Cereals are monocotyledonous grass crops cultivated annually for the purpose of consumption. They are rich in fiber and energy. Examples of them include;
maize, barley, wheat, oat, rye, etc.Cereal drinks are processed drinks extracted from cereal crops through fermentation. They are rich in nutrients as they contain important sources of carbohydrates, dietary protein, and vitamins.
The ingredients present in a cereal drink are composed of essential elements such as:
copper, cobalt, iron, zinc, molybdenum, iodine, chromium, and selenium.Some of which are not listed in the nutrition facts are Iron, Calcium, and Zinc.
Therefore, we can conclude that the elements present in the ingredients of the cereal drink which are not listed in the nutrition facts can be Iron, Calcium, and Zinc.
Learn more about essential elements here:
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Sciences Grad Bosch Law of Conservation of Mass - Assess it
contents
Target: 10/2001
Science and Enging
Achemical reaction takes place in a closed system. The mass of the reactants before the reaction was
55 watte mass of the products of the reaction be according to the law of conservation
Properties of Matter
Answer:
55
Explanation:
According to the law of conservation properties of Matter in a closed system the mass of reactants is equal to the mass of products. Because there is no lose of matter or energy in closed system
What is a graph?
A graph is a _______________________ representation of the relationship between two quantities.
_______________________ variable (manipulated)
Controlled by experimenter
_______________________________ variable (responding)
Something we observe as the result of the experiment
*Visual
*Independent
*Dependent
Determine how you would prepare 220 mL of a 0.500 M potassium hydroxide solution starting with: a) solid potassium hydroxide b) a 1.25 M potassium hydroxide solution
Answer:
a) 6.17 g of solid KOH
b) 88.0 mL of a 1.25 M potassium hydroxide solution
Explanation:
a) We have to determine the mass of solid potassium hydroxide that has to be weighed to prepare 220 mL of a 0.500 M potassium hydroxide solution. We will also require the molar mass of potassium hydroxide, KOH, 56.11 g/mol.
0.220 L × (0.500 mol/L) × (56.11 g/mol) = 6.17 g
b) We will use the dilution rule to determine the volume of the 1.25 M potassium hydroxide solution to be measured.
C₁ × V₁ = C₂ × V₂
V₁ = C₂ × V₂ / C₁
V₁ = 0.500 M × 220 mL / 1.25 M = 88.0 mL
1.why does gravity exist?
2.what does the strength of gravity on?
3.what will have stronger force of gravity, jupiter or earth ?
This class is science !!
Answer:
Gravity exists because elementary particles (electrons, quarks, and neutrinos), are NOT static with time and expansion. Matter is dynamic; elementary particles must continually accrete energy (the quanta of space) in order to conserve the continually increasing angular momentum of the expanding universe.
Strength of gravity
9.80665 m/s 2
Jupiter
Burning 1 kg of coal releases about 3 million joules of energy. If you could use all of the chemical energy to lift another kilogram of coal, how high could you lift it?
I could lift 3.06 x 10⁵ m high
Further explanationEnergy is the ability to do work. Energy can change from one energy to another
Potential energy is the energy that an object has because of its position
The potential energy can be formulated:
Ep = m. g. h
E = potential energy of an object, joule
m = object mass, kg
g = gravity acceleration, m / s²
h = height of an object, m
energy of coal = 3.10⁶ J
mass = 1 kg
g = 9.8 m/s²
[tex]\tt h=\dfrac{E}{m.g}\\\\h=\dfrac{3.10^6}{1\times 9.8}=3.06\times 10^5`m[/tex]
A sample of gas has a volume of 10 ml at 2 atm. The pressure increases to 4 atm. What is the new volume?
Answer:
The answer is 5 mLExplanation:
In order to find the new volume we use the formula for Boyle's law which is
[tex]P_1V_1 = P_2V_2[/tex]
where
P1 is the initial pressure
P2 is the final pressure
V1 is the initial volume
V2 is the final volume
Since we are finding the new volume
[tex]V_2 = \frac{P_1V_1}{P_2} \\[/tex]
We have
[tex]V_2 = \frac{10 \times 2}{4} = \frac{20}{4} \\ [/tex]
We have the final answer as
5 mLHope this helps you
What is the oxidation number of Gallium?
Answer: +3
Explanation: Gallium liquefies just above room temperature. Gallium is a soft solid, however it quickly becomes liquid when heated.