Explanation:
Potassium is a chemical element with the symbol K and atomic number 19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmospheric oxygen to form flaky white potassium peroxide in only seconds of exposure
Answer:
alkali metalExplanation:
Potassium is a chemical element with symbol K and atomic number 19. Classified as an alkali metalPart B
4.80 x 1022 molecules of propane, C3Hg.
Express your answer with the appropriate units.
Calculate the mass in grams
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
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
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:
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
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.
Homer notices that his shower is covered in a strange green slime. His friend Barney tells him that coconut juice will get rid of the green slime. Homer decides to check this out by spraying half of the shower with coconut juice. He sprays the other half of the shower with water. After 3 days of "treatment" there is no change in the appearance of the green
Answer:
This strange green slime is a colonization of fungi caused by the humidity of the bathrooms, which to be eradicated requires a non-specific antimicrobial such as sodium hypochlorite that generates an osmotic imbalance producing a fungicidal effect.
Explanation:
The fungi that appear in the form of slime at the microscopic level have many forms of colonization, by adding coconut milk it was assumed that this would generate an environment not suitable for their metabolism and reproduction but this did not happen, therefore they continued their reproduction.
Answer:
Explain?
Explanation:
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:
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:
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.
For more details regarding terrestrial planets, visit:
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if water is raise up by 50K and it takes 20900J to do it, what is the mass of the water?
Answer:
100g
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.
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
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:
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
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:
What is the relationship between the latitude and hours of daylight
Answer:
The tilt of the Earth's axis also defines the length of daylight.Daylight hours are shortest in each hemisphere winter. Between summer and winter
solistice the number of daylight hours decreases and the rate of decrease is larger the higher the latitude.The fewer sunlight hours the colder nights.
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)
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:
The Greek philosopher Empedocles proposed the idea that
ALL matter was made of_____
elements.
Answer:
the four elements fire, air, water earth
Explanation:
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.
Which of the situations below describes an ethical dilemma related to food
engineering?
A. Educational seminars should be conducted to help consumers
grow their own crops.
B. Production plants should be located close to consumers so
distribution runs efficiently.
C. Pesticides protect our crops, but some European countries have
linked them to thyroid disorders.
D. Preservatives must be used so that food can reach the consumer
before spoiling
Answer:
C. Pesticides protect our crops, but some European countries have
linked them to thyroid disorders.
Explanation:
Researches involving human or sometimes animals are subject to critical decision making.
They can easily trespass on the fundamental rights of people and some other issues.
The use of pesticides on a crop which can lead to thyroid disorder is an ethical dilemma. In this case, the pesticide helps to prevent crop loss due to the invasion of pests. This will boost food production and ensure food is availableLikewise, the application of the pesticide causes thyroid issues. This is an ethical dilemma issue.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.
How do covalent bonds form?
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
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.
What is Mercury's proximity to the sun
Answer:
46.943 million km
Explanation:
From an average distance of 36 million miles (58 million kilometers), Mercury is 0.4 astronomical units away from the Sun.
Answer:
29.169 million miles
Explanation:
From an average distance of 36 million miles(58 million kilometers,Mercury is 0.4 astronomical units away from the sun.
Help this is not that hard I think
Answer:
1,) True
2.) False
3.) A Moraine
Explanation:
Hope this helps
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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
WILL GIVE BRAINLIEST
12) The chemical formula for phosphorus trichloride is PCl3. In one to two sentences, explain how you would build a ball-and-stick model of phosphorus trichloride. Include a description of the parts of the model.(2 points)
13) Copper (Cu) reacts with sulfur (S) to form copper sulfide as shown in the chemical equation. A scientist adds 4 grams of Cu to 2 grams of S to start the reaction. At the end of the experiment, she has 6 grams of product. In one to two sentences, explain what would happen if the scientist increased the amount of copper to 6 grams, and why. (1 point)
Answer:
12) In the ball and stick model, an orange ball representing the phosphorus atom and three green balls representing chlorine atoms are connected by means of sticks that are coloured halfway green and orange respectively to represent the shared electrons between phosphorus and chlorine with the chlorine atoms forming the base of a triangular pyramid while the phosphorus atom forms the top of the pyramid.
13) The scientist will have 6 grams of product as before but will have two grams of unreacted copper atoms because the mass ratio of copper to sulfur in this reaction is 2:1
Explanation:
12) Phosphorus trichloride has a trigonal pyramidal structure and is composed of three atoms of chlorine and one atom of phosphorus.
In the ball and stick model, an orange ball representing the phosphorus atom and three green balls representing chlorine atoms are connected by means of sticks that are coloured halfway green and orange respectively to represent the shared electrons between phosphorus and chlorine with the chlorine atoms forming the base of a triangular pyramid while the phosphorus atom forms the top of the pyramid.
13) The reaction between copper and sulfur to form copper sulfide is shown in the equation below:
Cu + S ---> CuS
1 mole of copper reacts with 1 mole of sulfur to produce 1 mole of copper sulfide
molar mass of copper = 64 g/mol; molar mass of sulfur = 32 g/mol, molar mass of copper sulfide = 96 g/mol
mass ratio of copper to sulfur = 63 g/ 34 g = 2
This means that 2 grams of copper will react with 1 g of sulfur to produce 3 grams of product. similarly, 4 g of copper will react with 2 g of sulfur to produce 6 grams of product.
Therefore 6 g of of copper will react with 3 g of sulfur. However, since the amount of sulfur available for reaction is 2 g only, 2 g of copper will be left unreacted after 4 g has reacted completely with 2 g of sulfur to produce 6 g of copper sulfide.