Answer:
C
Explanation:
If you move the decimal to the left it transforms the expression into scientific notation.
An unknown substance has a volume of 2 cm3 and a mass of 38.6 grams.
What is the density of the sample?
Answer:
The answer is 19.3 g/cm³Explanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\ [/tex]
From the question we have
[tex]density = \frac{38.6}{2} \\ [/tex]
We have the final answer as
19.3 g/cm³Hope this helps you
3. Which of the following is not a compound?
water
potassium iodide
B
sodium chloride
D hydrogen
Is a backpack a good resource
for a rescue team?
Which of the following is used for chemical symbols today? a. drawings c. letters b. icons d. numbers
Answer:
Letters
Explanation:
For example, today we use the periodic table which is full of elements named with 1 or 2 letters. Like how Helium is He and Sodium is Na. Hope this helps!!!
Chemical symbols are used to identify an element and it is represented by one or two letters from their latin name. Thus option c is correct.
What is chemical symbol?Chemical symbols are representations for elements and compounds. Each element in the periodic table have their own symbol which first letter or first two letters from their latin name.
For example, hydrogen has the symbol H, oxygen is O, N for nitrogen C for carbon, Na for sodium etc. The latin name of sodium is natrium, that's why it has the symbol Na.
The letters used in the chemical symbol must be capital. If two letters are there like in Na, Ar etc. the first letter be capital and second letter have to be in small case.
In a similar way compounds can be represented using chemical symbols with number of each atom given as subscripts of the elemental symbol as in CO₂, H₂O etc.
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Which phrase best describes igneous rocks?
form when lava and magma cool
accumulate sediments following erosion
require heat and pressure to be formed
consist of many sediment layers
ctivity
Answer:
A) form when lava and magma cool
please give me brainliest :p
God bless!
Answer:
A: form when lava and magma cools
Explanation:
Got it right on Edge 2020 :)
A dull metal object has a density of 8.8 G/ML and a volume of 20 ML calculate the mass
Answer:
Mass = 0.000176 gram
Steps:
m = V × ρ
= 20 milliliter × 8.8 gram/cubic meter
= 2.0E-5 cubic meter × 8.8 gram/cubic meter
= 0.000176 gram
Explanation:
How many moles are in 12.6 grams of K2S?
In which situation is it better to have low friction?
Choose the correct answer.
a skydiver uses a parachute
a student walks down a hallway
a ladder leans against the wall
a hockey puck slides toward the goal
Answer: D- a hockey puck slides toward the goal
Explanation:
It needs to be able to slide easily and thats the correct answer on the test
The quantum mechanical model...
a
describes electrons as moving through specific circular orbits, and not staying in one place.
b
places electrons in fixed positions, not moving through specific orbits or orbitals.
c
describes electrons as moving anywhere in the atom, not specific circular orbits.
d
describes electrons as moving through cloud-like orbitals, not specific circular orbits.
Write a complete, balanced chemical equation where tin metal reacts with aqueous hydrochloric acid to produce tin(II) chloride and hydrogen gas. Include states.
From the equation, which element is oxidized, and which element is reduced?
Answer:
1. The balanced equation is given below:
Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)
2a. H is oxidized.
2b. Sn is reduced.
Explanation:
1. Balanced equation for the reaction between tin (Sn) metal and aqueous hydrochloric acid (HCl) to produce tin(II) chloride (SnCl₂) and hydrogen gas (H₂).
This is illustrated below:
Sn (s) + HCl (aq) –> SnCl₂ (aq) + H₂ (g)
There are 2 atoms of Cl on the right side and 1 atom on the left side. It can be balance by putting 2 in front of HCl as shown below:
Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)
Now, the equation is balanced
2. Determination of the element that is oxidize and reduced.
This can be obtained as follow:
We shall determine the change in oxidation number of each element.
NOTE:
a. The oxidation number of H is always +1 except in hydrides where it is –1.
b. The oxidation state of Cl is always –1.
Sn (s) + 2HCl (aq) –> SnCl₂ (aq) + H₂ (g)
For Tin (Sn):
Sn = 0
SnCl₂ = 0
Sn + 2Cl = 0
Cl = – 1
Sn + 2(–1) = 0
Sn – 2 = 0
Collect like terms
Sn = 0 + 2
Sn = +2
Therefore, the oxidation number of Tin (Sn) changes from 0 to +2
For H:
H = +1
H₂ = 0
The oxidation number of H changes from +1 to 0
For Cl:
Cl is always –1. Therefore no change.
Summary:
Element >>Change in oxidation number
Sn >>>>>>>From 0 to +2
H >>>>>>>>From +1 to 0
Cl >>>>>>>No change
Therefore,
Sn is reduced since its oxidation number increased from 0 to +2.
H is oxidized since it oxidation number reduced from +1 to 0
The balanced chemical equation for the reaction is
Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)
and the element that oxidized is tin (Sn) while the element that is reduced is hydrogen (H)
The balanced chemical equation for the reaction where tin metal reacts with aqueous hydrochloric acid to produce tin(II) chloride and hydrogen gas is
Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)
From the equation,
The element that is oxidized is tin (Sn), because the oxidation state of Sn increased from 0 to +2
The element that is reduced is hydrogen (H), because the oxidation state of H decreased from +1 to 0.
Hence,
The balanced chemical equation for the reaction is
Sn(s) + 2HCl(aq) → SnCl₂(aq) + H₂(g)
and the element that oxidized is tin (Sn) while the element that is reduced is hydrogen (H).
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Question 2 of 10
What are Van der Waals forces?
A. Forces that change polar molecules into nonpolar molecules
B. Very strong forces that exist between two different molecules
O c. Hydrogen bonds in nonpolar molecules caused by a permanent
dipole
D. Small dipole attractions between molecules caused by a
temporary electron shift
SEB
Answer:
D
Explanation:
Van der Waal forces are small dipole attractions between molecules caused by a temporary electron shift ,here, the option D is correct.
What are Van Der Waal forces?Van der Waals forces exist among all kinds of atoms and molecules. The origin of this force stems from the instantaneous dipole-induced dipole interactions among adjacent polar atoms and molecules.
Among polar molecules, there are three components that contribute to the total forces: the induction force, the orientation force and the dispersion force.
The Van Der Waal forces that act between macroscopic bodies and surfaces in a solvent medium are relevant to the phenomena of protein adsorption.
Van Der Waal forces are the small dipole attractions between molecules caused by a temporary electron shift , thus, option D is correct.
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What is the mass, in grams, of 0.450 moles of Sb?
Answer:
54.9 g
Explanation:
0.450 mol x 122g/mol
Relative and average atomic mass both describe properties of an element related to its different isotopes. Out of these two Relative atomic mas is more accurate. Therefore, 54.9 g is the mass in grams of 0.450 moles of Sb.
What is mass?Mass defines the quantity of a substance. It is measured in gram or kilogram. Average mass is the mass of atoms of an element that are isotopes. It can be calculated by multiplying mass of a isotope to natural abundance of that isotope.
Average atomic mass = (mass of first isotope× percent abundance of first isotope)+(mass of second isotope× percent abundance of second isotope)
Mass of Sb= number of moles of Sb ×Molar mass of Sb
=0.450 mol x 122g/mol
=54.9 g
Therefore, 54.9 g is the mass in grams of 0.450 moles of Sb.
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Which of the following characteristics is shared by both primary and secondary consumers? I need it quick it please
A. Uses the Sun's radiant energy of produce food
B.The first step in an food chain diagram
C. Eats only plants to gain needed energy
D.Gains energy by eating other living things
Answer:
Gains energy by eating other living things
The statement 'gains energy by eating other living things' is a characteristic shared by both primary and secondary consumers (Option D).
Producers (e.g. algae and plants) are autotrophic organisms that generate their own food.Primary consumers and secondary consumers are heterotrophs that need to eat other organisms to survive.Primary consumers can be, for example, herbivores, whereas secondary consumers can be carnivores.In conclusion, the statement 'gains energy by eating other living things' is a characteristic shared by both primary and secondary consumers (Option D).
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Based on the article "Will the real atomic model please stand up?," describe what Dalton's theory states about a molecule of water. Dalton's theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.
Answer:
Follows are the solution to this question:
Explanation:
The characterization with water molecules would be that light waves are made up of 2 different types of atoms (2 hydrogen and 1 oxygen atoms), as per the Dalton theory. There are many multiple times as many atoms of hydrogen as oxygen atoms in each water molecules. For every two hydrogen atoms, all water molecules have one oxygen atom.
Answer:
Sample Response: Dalton’s theory about compounds tells us that all water molecules have different kinds of atoms, two hydrogen atoms for every one oxygen atom.
Explanation:
How does an object's mechanical energy change as its speed (velocity) increases?
Answer:
The mechanical energy of the system increases, provided there is no loss of energy due to friction. The energy would transform to kinetic energy when the speed is increasing. The mechanical energy of the system remains constant provided there is no loss of energy due to friction.
Explanation:
Identify whether each element is a halogen, a noble gas, or nonmetal only.
Astatine (At):
Nitrogen (N):
Krypton (Kr):
Chlorine (Cl):
Sulfur (S):
Answer:
Astatine: Halogen
Nitrogen: Non-Metal
Krypton: Non-Metal, Noble Gas
Chlorine: Non-Metal
Sulfur: Non-metal
Explanation:
Describe what will happen to the pressure of the gas as the plunger is pushed in.
Answer:
The pressure of gas will increase.
Explanation:
The question above is related to "Boyle's Law." According to this law, provided that the temperature and amount of gas are stable, the absolute pressure of gas is inversely proportional to its volume.
In this sense, if the plunger will be pushed in, the volume of the gas will definitely decrease due to lack of space while the pressure will increase because the molecules of the gas are colliding with each other. The greater the collision, the greater the pressure. This explains the answer above.
Chemistry Data Analysis --
7.86 x 10^-15 x 3.9 x 10^-10
Answer:
3.065 x 10^-24
Explanation:
hope this helps
Identify the mineral that can have the composition of KMg3AlSi3O10(OH)2
Answer:
Phlogopite
Explanation:
It is a member of mica group family of phyllosilicates mineral. It is the magnesium endmember of the biotite stable - the chemical formulation KMg3AlSi3O10 (F, OH) 2.
Please help me on Q2
I’ll be so incredibly grateful!!
Answer:
No. of neutrons = 27 - 13 = 14
No. of protons = No. of electrons = 13
Hope it helps you
If a wave of red light has a wavelength of 6.7 x 10-7 m, will the frequency of the red wave be high or low?
Answer:
Its high
Explanation:
Becuase if u times it what do u get
Who still uppppppp and boreddddd
Answer:
me
Explanation:
What mass does 4.41 moles of cobalt have? Help!!!!
Answer:
260 g
Explanation:
Data obtained from the question include:
Mole of cobalt (Co) = 4.41 moles
Mass of cobalt (Co) =...?
The mole of a substance is related to its mass according to the following equation:
Mole = mass / Molar mass.
With the above formula, we can obtain the mass of 4.41 moles of cobalt as follow:
Mole of cobalt (Co) = 4.41 moles
Molar mass of cobalt = 59 g/mol
Mass of cobalt (Co) =...?
Mole = mass /Molar
4.41 = mass / 59
Cross multiply
Mass of cobalt = 4.41 × 59
Mass of cobalt = 260 g
Therefore, the mass of 4.41 moles of cobalt is 260 g
(100 POINTS) When thermal energy (heat) is added to a reaction, it happens _________ (faster or slower)
When thermal energy (heat) is removed from a reaction, it happens _________ (faster or slower)
Answer:
1) faster
2) slower
Explanation:
Answer:
faster
Explanation:
Determine the amount of energy (heat) in Joules and Kcal required to raise the temperature 0f 98.5 grams water from 37.0 0C to 75.0 0C.
Answer:
15660.712J
Explanation:
Q = m × c × del T
Q(energy) = ?
m (mass) = 98.5g
c = 4.184J
del T = 75-37 = 38 °C
Q = 98.5 × 4.184 × 38
Q = 15660.712 J
Two compounds of phosphorus and fluorine have the following
mass ratios.
Compound 1: 10.14 g fluorine for every 3.38 g phosphorus
Compound 2: 8.42 g fluorine for every 4.21 g phosphorus
Find the whole number ratio of masses of fluorine in compound
1 to compound 2.
Help me please
Answer: 3:2
Explanation: (10.14÷3.38)÷(8.42÷4.21)=1.5=3/2
How would an astronomer identify our home in the universe? Earth is in the solar system. The Milky Way is in the solar system. The solar system is next to the Milky Way. Earth is in the Milky Way and next to the solar system. The Milky Way is in the universe. The solar system is in the Milky Way. Earth is in the solar system. The universe is in the Milky Way. The Earth is in the Milky Way. Earth is at the center of the solar system.
Answer:
Earth is in the solar system.
Explanation:
Earth is our home and it is in the solar system.
Earth is the fifth-largest of the planets in the solar system and the third planet from the sun. Earth is the only planet having oxygen and water that supports life. Till now according to the research Earth is the only planet having life.
Planets are in the solar system, the solar system is in the milky way and the milky way is present in the universe. The astronomer identifies our home in the universe as "Earth is in the solar system" as Earth is our home.
Hence, the correct answer is "Earth is in the solar system."
Answer:
The Milky Way is in the universe. The solar system is in the Milky Way. Earth is in the solar system.
Explanation:
If the Milky Way Is in the universe and solar system you would know earth is also In the solar system, so "Our home planet is the third planet from the Sun, and the only place we know of so far that's inhabited by living things. While Earth is only the fifth largest planet in the solar system, it is the only world in our solar system with liquid water on the surface."
Calculate the heat that must be supplied to
a 532 , stainless steel vessel containing 375 g
of water to raise its temperature from 35 C
to the boiling point of water 100°C. Cs. =0.51 J/g. degrees C
Answer in units of J.
Q must be supplied = 119523.3~J
Further explanationThe law of conservation of energy can be applied to heat changes, i.e. the heat received/absorbed is the same as the heat released
Q in = Q out
Heat can be calculated using the formula:
Q = mc∆T
Q = heat, J
m = mass, g
c = specific heat, joules / g ° C
∆T = temperature difference, ° C / K
So from the question :
Q to the system(Q supplied) = Q water + Q steel vessel(Q gained)
[tex]\tt Q~supplied=m.c\Delta T(water)+m.c\Delta T(vessel)\\\\Q~supplied=375\times 4.18\times (100-35)+532\times 0.51(100-35)\\\\Q~supplied=101887.5+17635.8=119523.3~J[/tex]
If the black dot is sound, which direction is the sound in the picture moving? *
Answer:
Left or up, either one of those
Explanation:
Answer:
isnt the answer RIGHT
Explanation:
The bright red line from the emission spectrum of hydrogen has a wavelength of 657 nm. What is the energy, in joules, of a single photon of this light? 4.35 x 10–40 J 3.03 x 10–28 J 3.03 x 10–19 J 4.56 x 1014 J
Answer:
3.03 × 10^-19 J
Explanation:
The energy, E, of a photon of light can be calculated by using the formula:
E = hv
Where; E is energy in Joules,
h is Planck's constant {6.626×10^−34J}
v is frequency of light
For this question, the wavelength (λ) is given, not the frequency (v).
Hence, we use;
v= c/λ
Where v= frequency, c= speed of light (3×10^8m/s), λ= wavelength (657nm)
657nm = 657 × 10^-9m
v = 3×10^8/657 × 10^-9
v = 3/657 × 10^(8--9)
v = 0.00456 × 10^17
v = 4.56 × 10^14
Since frequency (v) = 4.56 × 10^14;
E = hv
E = 6.626×10^−34 × 4.56 × 10^14
E = 30.21 × 10^(-34+14)
E = 30.21 × 10^-20
E = 3.021 × 10^-19
Therefore, the energy of the photon of light is 3.02 × 10^-19 J