8. What is one sign that the water in your house is "hard?"
Answer:
More than soap sc um, hard-to-remove scale or film is often due to hard water. Also, take a good look at your faucets or fixtures.
Explanation:
hope this helps :D
Plz help it's due soon. Calculate the energy and frequency of red light having a wavelength of 6.55 x 10⁻7m.
Answer:
E = 3.035× 10-¹⁹J = 1.9eV
f = 4.58 × 10¹⁴Hz
Explanation:
wavelength = 6.55 × 10-⁷m
c = 3 × 10⁸m/s
f = ?
E = ?
a) f = c/wavelength
f = 3 × 10⁸/6.55 × 10-⁷
f = 4.58 × 10¹⁴Hz
b) E = hc/wavelength
E = 6.626×10-³⁴ × 3 × 10⁸/ 6.55 × 10-⁷
E = 3.035 × 10-¹⁹J
1ev = 1.6 × 10-¹⁹J
Therefore E = 3.035/1.6 = 1.9eV
Hope it's not too late man
How many moles are in 2.8 g of Mg?
Answer:
2.8 mg ≈ 0.12 mol
If the wavelength of purple light is 400 x 10^-9 m, what is the frequency?
a) 7.5 x 10^14 /s
b) 8 X 10^14 Hz
c) 7.5 x 10^14 m
d) 8 x 10^14 m
The frequency : a) 7.5 x 10¹⁴ /s
Further explanationRadiation energy is absorbed by photons
The energy in one photon can be formulated as
[tex]\large{\boxed{\bold{E\:=\:h\:.\:f}}}[/tex]
Where
h = Planck's constant (6,626.10⁻³⁴ Js)
f = Frequency of electromagnetic waves (/s or Hz)
f = c / λ
c = speed of light
= 3.10⁸ m/s
λ = wavelength
The wavelength(λ) of purple light is 400 x 10⁻⁹ m, so the frequency :
[tex]\tt f=\dfrac{c}{\lambda}\\\\f=\dfrac{3.10^8~m/s}{4.10^{-7}m}\\\\f=\boxed{\bold{7.5.10^{14}}/s}[/tex]
Which best represents the law of conservation of mass?
mass of reactants > mass of products
mass of reactants < mass of products
mass of reactants = mass of products
mass of reactants → mass of products
Answer:
mass of reactants mass of products
Answer:
C. mass of reactants = mass of products
Explanation:
I just took the test. Hope this helps and good luck!
advantages of soapy detergents
Answer:
Soapy detergents clean more effectively than normal soap. Hard water (water with high mineral content). Hard water can be used with soapy detergents but soap cannot be used with hard water. When soapy detergent and hard water are combined it makes a protective film that is really resistant to rinsing.
Have a good day.
how can you tell if a chemical is an ionic bond?
How can you use electrons to determine the identity of an element?
Answer:
The number of protons in one atom of an element determines the atom's identity, and the number of electrons determines its electrical charge. The atomic number tells you the number of protons in one atom of an element. It also tells you the number of electrons in a neutral atom of that element.
Explanation:
Answer:
The number of protons in one atom of an element determines the atom's identity, and the number of electrons determines its electrical charge. The atomic number tells you the number of protons in one atom of an element. It also tells you the number of electrons in a neutral atom of that element.
Explanation:
Ionic compounds blank
in water.
are extremely soluble
are slightly soluble
have varying solubilitieS
Which pair of elements will form an ionic bond?
A. nitrogen and oxygen
B. carbon and chlorine
C. barium and chlorine
D. carbon and oxygen
Answer:
Barium and chlorine
Explanation:
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i need help on this its due Monday
The properties of the elements can be determined from their electron configuration
Further explanationMg ⇒electron configuration :[Ne] 3s²outer electron : 2 (3s²)
lose(2 electron)
charge : +2
cation (positive)
symbol : Mg²⁺
Br⇒electron configuration : [Ar] 4s²3d¹⁰4p⁵outer electron : 7 (4s²4p⁵)
gain ( 1 electron)
charge : -1
anion (negative)
symbol : Br⁻
Helium⇒electron configuration : 1s²
outer electron : 2 (1s²)
stabil(no gain/no lose)
charge : 0
neutral
symbol : He
Nitrogen ⇒electron configuration : [He] 2s²2p³outer electron : 5 ( 2s²2p³)
gain(3 electron)
charge : -3
anion
symbol : N³⁻
Multimeters are used to test the conductivity of a substance. What is most likely the identity of the liquid?
Answer:
The purpose of this lab is to determine the identity of an unknown liquid by measuring its density, melting point, boiling point, and solubility in both water and alcohol, and then comparing the results to the values for the known substance. Hope this helps!! :)
A gas originally at a pressure of 791 mm Hg and a volume of 500.0 mL is allowed to
expand to 1.00 Liter. What is the new pressure of the gas? (Boyle)
Answer:
The new pressure of the gas is 395.5mmHg
Explanation:
The pressure of a gas is inversely proportional to its concentration (Boyle's law). The equation that explain this law is:
P₁V₁ = P₂V₂
Where P is pressure
And V is volume of 1, initial state and 2, final state of the gas
Initial state:
791mmHg; 0.500L.
Final state:
1.00L
Replacing:
791mmHg* 0.500L = P₂*1.00L
P₂ = 395.5mmHg
The new pressure of the gas is 395.5mmHgDescribe the relationship between the solubility rate of a solid and temperature.
Answer:
hope you like
Explanation:
the solubility rate of a solid is directly proportional to the temperature. if the temperature is high the solubility will also increase
There is enough energy in air at room temperature to change some
liquids to gases.
True or False
Answer:
hi
Explanation:
There is enough energy in air at room temperature to change some liquids to gases. The temperature of ice water is lower than the temperature of dry ice in alcohol. Carbon dioxide can change directly from the solid phase to the gaseous phase. ... Absolute zero is the temperature at which there is no molecular motion.
Answer: True
What is the valency of aluminum in aluminum chloride?
A. 1
B.2
C.3
D.4
Answer:
C.3
13AL
2.8.3
The number of electrons from the outermost shell is the valence of the element.
A 800 kg car zooms away from a red light with an acceleration of 7.6 m/s2. What is the
average net force in Newtons that the car experiences?
Answer:
Fnet = 13920 Newtons
Explanation:
Net force can be defined as the vector sum of all the forces acting on a body or an object i.e the sum of all forces acting simultaneously on a body or an object.
Mathematically, net force is given by the formula;
[tex] Fnet = Fapp + Fg[/tex]
Where;
Fnet is the net force Fapp is the applied forceFg is the force due to gravitationGiven the following data;
Mass, m = 800 kg
Acceleration, a = 7.6m/s²
To find the applied force;
[tex] Fapp = ma[/tex]
Substituting into the equation, we have;
[tex] Fapp = 800 * 7.6[/tex]
Fapp = 6080N
To find the gravitational force;
We know that acceleration due to gravity, g = 9.8m/s²
[tex] Fg = mg[/tex]
Substituting into the equation;
[tex] Fg = 800 * 9.8[/tex]
Fg = 7840N
To find the net force;
[tex] Fnet = Fapp + Fg[/tex]
Substituting into the equation, we have;
[tex] Fnet = 6080N + 7840N[/tex]
Fnet = 13920 Newton.
Therefore, the net force experienced is 13920 Newton.
PLZ HELP GIVING BRAINLEST TO WHO EVER HELPS AND GETS THE RIGHT ANSWER. Plz and tysm
The pavement on a hot day has transformed light energy from______ to heat energy.
1. Radiation
2. Conduction
3. Convection
4.All of the above
Answer:
4. all the above
Explanation:
It's all of the above because Thermal energy has all three. An example is like a pot of water on the stove boiling. Radiation is coming off of the eye of the stove. Conduction occurs when heat transfers from hot to cold ( like the handle of the pot). Convection occurs in the boiling of the water by rotating causing the heat to rise.
Hello can someone help me out i will give brainliest. Chemical or physical change hw
Answer:
20 and 24 are chemical the rest are physical
Answer:
1. Fireworks: chemical,
2. Hair: physical
3. glow sticks: chemical
4.Baseball: physical
5.Popcorn: chemical
Explanation:
1. bc there are chemicals/powders
2. the hair is still hair, even if it is cut
3. You are combining chemicals, this cannot be un-done
4. The shards are still glass, they do not turn into another substance other than glass
5. You heated the popcorn, it "exploded", this cannot be undone
Atoms in Group 18(8A) are inert (chemically unreactive) because
A
they combined to form molecules.
B
they have no valence electrons.
С
they have filled inner energy levels.
D
they have a full valence shell.
Answer: They combined to form molecules.
Explanation:
That statement that describes atoms in Group 18(8A) are inert is "they have a full valence shell."
What is chemically inert?A substance that is not chemically reactive is referred to as chemically inert.
When elements react, their atoms lose, gain, or share electrons to complete their outer shells. Noble gas atoms already have entire outer shells, therefore they don't inclined to lose, gain, or share electrons. This is why noble gases are chemically inert and do not participate in reactions.
When atoms bond, they try to form an octet by transferring or sharing valence electrons in the case of ionic bonds and covalent bonds, respectively. There is no incentive for group 18 atoms to bond because they already have an octet of valence electrons.
As a result, the noble gases belong to the periodic table's group 18. They are nonmetal elements with a full shell of valence electrons that are chemically inert, colourless, and odourless. We can see that helium (atomic number 2) has a full shell of two s electrons if we look at the electron configurations.
Hence the correct option is D.
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What makes up a film badge?
an electrolyte paste spread across a plastic sheet
a thin film of salts and other chemicals on clear acetate
layers of photographic film covered in black paper
a panel of photographic film exposed to the air
Film badges is a personal dosimeter used for monitoring cumulative radiation dose due to ionizing radiation.
A panel or layers of photographic film covered with black paper and exposed to air ,salt,and other chemicals on clear acetate
Answer:
layers of photo graphic film covered in black paper
Explanation:
The badge consists of two parts: photographic film and a holder.[1] The film emulsion is black and white photographic film with varying grain size to affect its sensitivity to incident radiation such as gamma rays, X-rays and beta particles.
What is the composition of sucrose?
Answer:
Sucrose is made up of one glucose and one fructose molecule, and are joined together by a glycosidic bond
Explanation:
Aqueous solutions of lithium bromide and silver nitrate are mixed.
Precipitate:
Chemical Equation:
Complete Ionic Equation:
Net ionic Equation:
Answer:
Chemical equation: AgNo3 + LiBr = AgBr + LiNO3
Explanation:
Answer:
Chemical equation: AgNO3 + LiBr -> AgBr + LiNO3
Complete Ionic equation: Ag + NO3 + Li + Br -> AgBr + Li + NO3
Net Ionic equation: Ag + Br -> AgBr
Explanation:
You start out with the chemical equation. We know that to get to the complete ionic equation we have to follow the solubility guidelines for common ionic compounds. In there, we can see that NO3 is soluble with no exceptions, which means every NO3 in this equation should be separated from the compound (this brings us to Ag + NO3 + LiBr -> AgBr + Li + NO3). Next we should separate Br, but be careufl because in the solubility guidelines it states that an exception to this being soluble would be if Br was next to Ag, Hg, and Pb. Since our second Br is next to an Ag, our equation will look like Ag + NO3 + Li + Br -> AgBr + Li + NO3. To find the net ionic equation all we're going to need to find are the substances that cancel each other out on both sides of the equation (aka the spectator ions). Our spectator ions in this case are Li and NO3. After we cancel those out, our net ionic equation is Ag + Br -> AgBr.
Which one of the following is not a property of a base?
A. Feels slippery
B. Reacts with limestone to produce carbon dioxide
C. Reacts with litmus paper and turns it blue
D. Tastes bitter
Answer:
option B is correct
Explanation:
What kind of reaction happens when two compounds switch elements?
A. A double-replacement reaction
B. A single-replacement reaction
C. A synthesis reaction
D. A decomposition reaction
Answer:
A
Explanation:
For a material to float on the surface of water, the material must have a density
less than that of water (1.0 g/ml) and must not react with the water or dissolve in
it. A spherical ball has a radius of 0.50 cm and weighs 2.0 g. Will this ball float or
sink when placed in water? (Note: Volume of a sphere = 4/3(pi)(r^3)
Answer:
Explanation:
volume of spherical ball = 4/3 x π R³
= 4 x 3.14 x .5³ / 3
= .5233 cm³ or ml.
mass = 2 g
density = mass / volume
= 2 / .5233
= 3.8 g / ml .
So its density is more than that of water , hence it will sink into water .
Which is the correct orbital diagram for carbon?
ОА.
1s
2s
2p
OB.
1s
2s
2p
112 1
2p
Ос.
1s
2s
OD.
1s
2s
2p
11
The modern periodic table consists of the elements which are arranged in the increasing order of their atomic numbers. The element 'C' belongs to 14th group of the periodic table. The correct option is A.
What is orbital diagram?The orbital diagrams are the pictorial representation of the electrons in an atom. The orbital diagrams are mainly based on the Auf Bau principle, Pauli's exclusion principle and Hund's rule of maximum multiplicity.
According to Auf Bau principle, the electrons are arranged in the orbitals in the increasing order of their energies. The pauli's exclusion principle states that no two electrons in an atom can have the same set of four quantum numbers.
The hund's rule states that the unpaired electrons in the orbitals have parallel spins. The atomic number of 'C' is 6, and its electronic configuration is 1s²2s²2p².
Thus the correct option is A.
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what is the classification of mixture
Answer:
classification of mixtures will be: solutions, suspensions, and colloids
Hopefully this helped
A neighbor wants to use his backyard garden to
conduct an investigation of how tomato plants use specific amounts of
carbon dioxide and water to grow at a certain rate. Is this a good idea?
Explain.
Answer:
No, it is not
Explanation:
The reason for this answer is below
To conduct an experiment/investigation that involves the use of specific amounts of carbon dioxide and water by plants, one needs a controlled environment where the amount of carbon dioxide and water made available to the plant can be monitored and regulated as desired by the experimental design. The neighbor's backyard cannot provide this controlled environment and thus it is a bad idea.
Note that the neighbor's backyard cannot provide the controlled environment because the amount of carbon dioxide the plants will be exposed to there cannot be regulated as this is the carbon dioxide from the atmosphere and also the plants could get additional water from midnight dew which cannot be regulated also.
It is a good idea to use backyard garden to conduct an investigation of
how tomato plants use specific amounts of carbon dioxide and water to
grow at a certain rate.
To obtain an accurate result, experiments should be done in an
environment which is similar to those in which plants are exposed to during
photosynthetic reactions.
The use of the backyard garden will have different factors such as
atmospheric pressure, sunlight, precipitation which the plants are exposed to
in its normal environment which is why it is a good idea.
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An atom of alluminum has an atomic number of 13 and a mass of a mass number lf 27. How many neutrons does it have?
Answer:
13 Neutrons
Explanation:
Answer:
14 neutrons!
Explanation:
The mass number is the total number of protons and neutrons in a nucleus. The atomic number is the number of protons in the nucleus.
So... 27−13=14 neutrons