Answer:
Mendeleev realized that the physical and chemical properties of elements were related to their atomic mass in a 'periodic' way, and arranged them so that groups of elements with similar properties fell into vertical columns in his table.
Explanation:
Explain what happens if the nucleus, of an atom, becomes unstable.
Answer:The unstable nucleus of radioactive atoms emit radiation. When this occurs, a new atom and element are formed. This process is called radioactive decay. It continues until the forces in the unstable nucleus are balanced.
Explanation:
List the different sizes of sediment.
Answer:
Smallest to Largest:
Clay is smaller then 1/125 mm
Silt is 1/256- 1/16 mm
Sand is 1/16-2 mm
Pebble is 2-64 mm
Cobble is 64-256 mm
Boulder is greater then 256 mm
Explanation:
Which of the following is the proper scientific notation for the number
18,200?
O A. .182 x 105
B. 1.82 x 104
O c. 18200 x 100
O D. 182 x 102
The Answer fam is......... 1.82 × 10^4, Hence It's B)
Help this is not that hard I think
Answer:
1,) True
2.) False
3.) A Moraine
Explanation:
Hope this helps
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You find a clear gem that is made of one substance. What could you do to
identify whether the gem is a diamond?
Answer:
You could have a scratch test, fog test, break test, theres many tests you could perform to see if it is a diamond.
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
Consider a 5.430 g mixture of FeO and Fe3O4. You react this mixture with excess of oxygen to form 5.779 g Fe2O3. Calculate the percent mass of FeO in the original mixture.
Answer:
Explanation:
A 5.430 g mixture of FeO and Fe3O4 is reacted with excess of oxygen to form 5.779 g Fe2O3. Find the masses of FeO and Fe3O4 present in the mixture.
I found the answer by doing the following:
Fe2O3 = 159.69 g/mol
FeO = 71.745 g/mol
Fe3O4 = 231.535 g/mol
5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3
x + y :rarrow: 0.03619 mol Fe2O3, where x = FeO and y = Fe3O4.
This implies that y = 0.03619 - x.
5.430 g = x*71.745 g/mol + (0.03619 - x)*231.535g/mol
x = 0.01846 mol * 71.745 g/mol = 1.324 g FeO
y = 0.03619 - 0.01846 = 0.01773 mol * 231.535 g/mol = 4.105 g Fe3O4
My question is why doesn't the following work:
4FeO + O2 :rarrow: 2Fe2O3
4Fe3O4 + O2 :rarrow: 6Fe2O3
_______________________
2FeO + 2Fe3O4 + O2 :rarrow: 4Fe2O3
5.779 g Fe2O3 / 159.69 g/mol = 0.03619 mol Fe2O3
Product:reactants in question are in a 2:1 ratio as given by the stoichiometric coefficients.
0.03619 mol / 2 = 0.01810 mol of FeO and 0.01810 mol Fe3O4.
0.01810 mol FeO * 71.745 g/mol = 1.299 g FeO
0.01810 mol Fe3O4 * 231.535 g/mol = 4.191 g Fe3O4
Obviously this doesn't work because the original mixture is 5.430 g and not 1.299 g + 4.191 g = 5.490 g. Why doesn't this work the way I think it should? Thank you.
Planets A and B are both the same size, but planet B has three times the mass of planet A. How does the weight of an object compare on the two planets?
Choose the correct answer.
The weight of an object is the same on both planets.
The weight of an object is three times larger on planet A.
The weight of an object is three times larger on planet B.
The weight of an object will depend on more factors than just the weight and size of the planet.
Answer:
The answer is d
Explanation:
Use the information below to answer the following questions.
Cyanobacteria, also known as blue-green algae, are a kind of bacteria found in many lakes. These organisms make their own food through photosynthesis. Small animals including mayfly larvae eat the cyanobacteria, and small fish such as yellow perch eat the larvae. The small fish provide food for larger fish, such as walleye.
Describe a model you could use to show the transfer of energy within the lake ecosystem. In your description of your model, make sure you include the position of each organism identified in the paragraph.
Answer:
sorry don't know wish I could help
Given: (52.6 cm)(1.214 cm)
What is the product expressed to the correct number of significant figures?
1.
64 cm2
2.
63.9 cm2
3.
63.86 cm2
4.
63.8564 cm2
Answer:
2.
63.9 cm2
Explanation:
All non-zero digits are consider significant figures like 1, 2, 3, 4, 5, 6, 7, 8, 9.
Leading zeros are not consider as a significant figures. e.g. 0.06 in this number only one significant figure present which is 6.
Zero between the non zero digits are consider significant like 108 consist of three significant figures.
The zeros at the right side e.g 240000 are also significant. There are six significant figures are present.
When we add or subtract the values the number of significant figures after decimal in result must be equal to the given measurement having less number of decimal places. For example,
The difference between 7.69 and 4.0.
7.69 - 4.0 = 3.7
When we multiply or divide the values the number of significant figures must be equal to the less number of significant figures in given value.
For example in given q:
52.6 cm × 1.214 cm = 63.9 cm²
What was Pangea and when did it form?
Answer:
Pangaea or Pangea ( /pænˈdʒiːə/) was a supercontinent that existed during the late Paleozoic and early Mesozoic eras. It assembled from earlier continental units approximately 335 million years ago, and it began to break apart about 175 million years ago.
Explanation:
which of the following is not a name given for the four outer plantets
1. gas Giants
2. Jovian planets
3. Terrestrial planets
The one that is not a name given for the four outer planets terrestrial planets. The correct option is 3.
What are Terrestrial planets?The planets Mercury, Venus, Earth, and Mars are referred to as terrestrial because their surfaces are compact and rocky, similar to Earth's terra firma. The terrestrial planets are the solar system's four innermost planets.
A terrestrial planet, telluric planet, or rocky planet is one that is primarily composed of silicate rocks or metals.
Mercury, Venus, Earth, and Mars are the inner planets in the Solar System that are closest to the Sun and are classified as terrestrial planets by the International Astronomical Union.
Astronomers who use the geophysical definition of a planet may consider two or three planetary-mass satellites, including the Earth's Moon, Io, and occasionally Europa, as terrestrial planets, along with the rocky protoplanet-asteroids Pallas and Vesta.
Thus, the correct option is 3.
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The heat required to raise the temperature of 12g of water from 16 C to 21 C is:
a) 60 J
b) 60 cal
c) 50 cal
d) 50 J
Answer:
The correct option is;
b) 60 cal
Explanation:
The mass of the given water, m = 12 g
The initial temperature of he given water = 16°C
The final temperature of the given water = 21°C
The specific heat capacity of water, c = 4.184 J/(g·°C) = 1 cal/(g·°C)
The amount of heat, ΔQ, required = Mass × Specific heat capacity × Change in temperature
ΔQ = 12 × 4.184 × (21 - 16) = 251.04 J
Similarly, we have;
ΔQ = 12 g × 1 cal/(g·°C) × (21 - 16)°C = 60 cal
The amount of heat required = 60 cal.
What is the correct order of increasing elec-
tronegativity?
1. Si, P, S, C, N, O, F
2. O, C, N, S, P, Si, F
3. F, Si, P, S, N, C, O
4. F, O, N, C, S, P, Si
Answer:
ceo que3
Explanation:
Michelle learns in science class that simple machines such as an inclined plane can change the amount of force needed to lift heavy objects. She decides to test this with an experiment.
Michelle chooses a 10 kg weight. She sets up a ramp made of smooth metal that makes an angle θ with the floor. She attaches a spring scale to the weight and the top of the ramp in order to hold the weight in place. She records the force from the spring scale, then changes θ and records it again. She repeats this several times.
In this experiment, what is the dependent variable?
A.
the mass of the weight
B.
the angle θ between the ramp and the ground
C.
the amount of force on the spring scale
D.
the material the ramp is made of
Be fast please
what do waves carry from place to place
Answer:
Waves carry energy from place to place.
Explanation:
Some waves are used for mainly communication and phone signals. They help people get internet in the middle of nowhere if you are near an energy wave.
what is the average distance between the sun and earth in summer and winter
Answer:
93,000,000 miles (8.5 light minutes)
Explanation:
In the northern hemisphere's winter, the earth is slightly closer to the sun than in the southern hemisphere's winter season
Part 1 Designing an Investigation
Melinda was cooking a pizza and removed the pizza from the
oven, which was set to 400 degrees Fahrenheit. She wanted to
cool down the pizza as quickly as possible to eat it. In her house,
she had a freezer (set to 0 degrees Fahrenheit), a refrigerator
(set to 40 degrees Fahrenheit), and the countertop (which is at
the temperature of the room, 78 degrees Fahrenheit).
1. Design an experiment that will let Melinda study which of
the three options, the refrigerator, the freezer, or the room, will let the pizza cool down the fastest.
Experimental Question (How does (IV) the heat
affect the pizza to cool down
DV)
Independent Variable
Dependent Variable
Experiment Plan
Answer:
The experimental plan is to measure the values of the dependent variable, which is the temperature of the pizza after it is cooled in each of the heat (temperature) environments, which is the dependent variable, for a given equal period of time, which is the control
Explanation:
The given parameters are;
The temperature of the pizza = 400°F
The temperature of the freezer = 0°F
The temperature of the refrigerator = 40°F
The temperature of the countertop = 78°F
Given that the independent variable = The heat to which the hot pizza is subjected
The dependent variable = The temperature to which the pizza cools down
The experiment plan includes;
1) Place the pizza which is at 400°F in each of the different heat environment, which are, the freezer, the fridge, and the counter top, for the same period of time and record the final temperature of the pizza
2) The option that gives the lowest final temperature within the same time frame is the option that will let the pizza cool down fastest.
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.
A penny is 2.5 g. How many kilograms does a penny weigh?
Answer:
The penny now weighs 0.0025kg
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True or False: A Precipitate is a solid
that forms out of a liquid solution as a
result of a chemical reaction
Answer:
true because it undergoes a tranformation
Explanation:
Solid substance A has a melting point of 100°C. Liquid substance B has a freezing point of 110°C. For each substance, identify its state of matter and describe the motion of its particles when the substance is at 115°C.
Answer:
both will be at liquid state. the particles will move rapidly in all directions and will collide with other particles in random motion
Is the study of the living plants and animals in the ocean
Answer:
marine biologist
Explanation:
marine biologist
Answer:
marine biologist a scientist who studies creatures that live in ocean water, from bacteria and shellfish to kelp and whales. mean One of several measures of the “average size” of a data set. .organism Any living thing, from elephants and plants to bacteria and other types of single-celled life.
Part B
4.80 x 1022 molecules of propane, C3Hg.
Express your answer with the appropriate units.
Calculate the mass in grams
Refer to your periodic table:
Which of the following has the smallest atomic radius?
Bromine
Astatine
Iodine
Fluorine
iondine
Explanation:
bromine has 185pm, astatine haa 200, iondine has 140 and lastly fluorine has 147. so iondine has the smallest atomic radius
what chemical is C2H4O2
Answer:
C2H4O2 is Acetic acid.
Explanation:
Acetic acid is a colourless liquid organic compound with the chemical formula CH3COOH (also written as CH3CO2H or C2H4O2). It is in the department of a chemical compound known as Glycolaldehyde. It is the smallest possible molecule that contains both an aldehyde group and a hydroxyl group.
How do covalent bonds form?
4. Calculate the energy (E) and wavelength (1) of a photon of light with a frequency of
6.165 x 1014 Hz.
PLEASE HELP!!
Answer: E= 4.085 x 10^-19 J ; Wavelength= 4.862 x 10^-7 m
Explanation:
Sorry for the messy work, but I hope this helps.
Remember:
Plancks constant (h)= 6.626x10^-34 Js
Speed of light (c) = 2.998 x 10^8 ms^-1
What I did:
I found the energy first with the given frequency. Don't forget to convert your units to s^-1! They are actually the same, you dont need to do math for that conversion, just a simple Hz to s^-1.
For the wavelength, I multiplied plancks constant (h) and speed of light (c) together. With that number I divided by the energy found which 4.085 x 10^-19J. Also, be sure to cross off the units because it can get very confusing.
The energy of the photon is 4.08 x 10⁻¹⁹ J
The wavelength of the photon is 2.58 x 10⁻⁶ m
The given parameters;
frequency of the photon, f = 6.165 x 10¹⁴ Hz
The energy of the photon is calculated as;
E = hf
where;
h is Planck's constant = 6.626 x 10⁻³⁴ Js
E = (6.626 x 10⁻³⁴)( 6.165 x 10¹⁴)
E = 4.08 x 10⁻¹⁹ J
The wavelength of the photon is calculated as;
v = fλ
where;
v is the speed of light = 3 x 10⁸ m/s
[tex]\lambda = \frac{v}{f} \\\\\lambda = \frac{3\times 10^8}{1.165\times 10^{14}} \\\\\lambda = 2.58 \times 10^{-6} \ m[/tex]
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Consider the following unbalanced equation.
Ca(OH)2 + (NH2)2SO4 → CaSO4 + NH3 + H2O
Help for 70 points please explain why too.
Answer:
1 Ca(OH)2 + 1 (NH4)2SO4 ---> 1 CaSO4 + 2 NH3 + 2 H2O
Explanation:
The photo I attached should make more sense as an explanation.
When balancing equations, the first and most important step is to count the # of each type of element on each side.
In this problem there are 5: Ca, O, H, N, and S.
Once you do that you can begin balancing.
Here is the initial tally for the elements in this problem:
On the left.....
Ca - 1
N - 2
S - 1
O - 6
H - 10
On the right.....
Ca - 1
N - 1
S - 1
O - 5
H - 5
Looking at these values, we can see N, O, and H all need adjusting the right side. You should never start balancing with O or H unless they are the only elements that need adjusting. They usually balance out with the rest of your work or with water in the end.
So given all of that, you should start balancing with N on the right. Giving NH3 a coefficient of 2 will change the number of Nitrogen atoms on the right to 2. Be careful though! It will also change the number of Hydrogen atoms from 5 to 8 (because (2*3) =6 and 6+2 =8).
Let's tally our numbers again.
On the left..... (these should be unchanged)
Ca - 1
N - 2
S - 1
O - 6
H - 10
On the right.....
Ca - 1
N - 2
S - 1
O - 5
H - 8
Okay, now we see only O and H need adjusting on the right. Luckily there is H2O so we can do that without impacting the number of other atoms.
Give H2O a coefficient of 2 and count the number of atoms on the right again.
On the right.....
Ca - 1
N - 2
S - 1
O - 6 (because 4 from CaSO4 plus 2 from 2H2O = 6)
H - 10 (6 from NH3 plus 4 from 2H2O = 10)
Do these numbers match what you have on the the left side of the equation? Yes! It is balanced so you do not need to adjust anymore. Your coefficients in the answer will be 1-1-1-2-2.
if water is raise up by 50K and it takes 20900J to do it, what is the mass of the water?
Answer:
100g
Explanation: