Answer:
3rd one
Explanation:
dont have one, i think just think it makes most sense
Answer:It is made up of a single element or type of compound
Explanation: This answer is right because for something to be pure it has to only be made up of 1 thing.
The process during which a substance changes from a solid directly to a gas without becoming a liquid is known as: Example(dry ice)
A)
condensation.
B)
fusion.
C)
melting.
D)
sublimation.
Tobacco use: The _____ _______ cause of ______ death
Answer:
Tobacco use: The most preventable cause of cancer death
Explanation:
cancer might not be right
Doing Calculations The metal thallium occurs naturally as 30 percent thallium-203 and 70
percent thallium-205. Calculate the atomic mass of thallium. Enter your numerical answer in
the blank provided please help
Answer:
Average atomic mass of thallium = 204.4 amu.
Explanation:
Given data:
Abundance of thallium-203 = 30%
Abundance of thallium-205 = 70%
Average atomic mass = ?
Solution:
Average atomic mass of thallium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100
Average atomic mass of thallium = (30%×203)+(70%×205) /100
Average atomic mass of thallium = 6090 + 14350 / 100
Average atomic mass of thallium = 20440 / 100
Average atomic mass of thallium = 204.4 amu.
II. Pure magnesium metal is often found as ribbons and can easily burn in the presence of oxygen. When 3.86 g of magnesium ribbon burns with 155ml of oxygen at 1.0 atm and 275 K , a bright, white light and a white, powdery product is formed, magnesium oxide. How many grams of excess reactant remain?
Answer:
[tex]Excess=3.53g[/tex]
Explanation:
Hello,
In this case, the undergoing chemical reaction is:
[tex]2Mg(s)+O_2(g) \rightarrow 2MgO(s)[/tex]
Next, we identify the limiting reactant by computing the moles of magnesium oxide yielded by 3.86 g of magnesium and 155 mL of oxygen at the given conditions via their 2:1:2 mole ratios and the ideal gas equation:
[tex]n_{MnO}^{by \ Mg}=3.86gMg*\frac{1molMg}{24.3gMg}*\frac{2molMgO}{2molMg} =0.159molMgO\\\\n_{MnO}^{by \ O_2}=\frac{1atm*0.155L}{0.082\frac{atm*L}{molO_2*K}*275K} *\frac{2mol MgO}{1molO_2} =0.0137molMgO[/tex]
It means that the limiting reactant is the oxygen as it yields the smallest amount of magnesium oxide. Next, we compute the mass of magnesium consumed the oxygen only:
[tex]m_{Mg}^{consumed}=0.0137molMgO*\frac{2molMg}{2molMgO} *\frac{24.3gMg}{1molMg} =0.334gMg[/tex]
Thus, the mass in excess is:
[tex]Excess=3.86g-0.334g\\\\Excess=3.53g[/tex]
Regards!
Which elements is the most reactive on this table?
Answer:
alkali metals
Explanation:
alkali metals only have one valence electron, meaning they are extremely reactive. they are considered the most reactive on the periodic table.
What is convection?
Transfer of heat through objects touching source
Transfer of heat through direct physical contact
Transfer of heat through electromagnetic waves
Transfer of heat through the movement of particles
Answer:
D.
Explanation:
What are the possible consequences of adding a chemical to the environment
Answer:
The release into the air of chemicals and particles can cause direct damage to the troposphere (air pollution); alter the composition and function of atmospheric layers (greenhouse effect) or other indirect damages (ozone layer depletion).
Explanation:
Watts are a measurement of power
Answer:
Watts are a measurement of power, describing the rate at which electricity is being used at a specific moment. For example, a 15-watt LED light bulb draws 15 watts of electricity at any moment when turned on. Watt-hours are a measurement of energy, describing the total amount of electricity used over time.
Please mark as brainliest.
Answer: True
Watts are a measurement of power, used in light bulbs and other electricity. It is also measured as candela (C) in SI Units. The answer to the question is true because of this measurement.
Hope this helps!
QUESTION 1
Consider the following reaction: CH4 + 202 --> 2H2O + CO2
How many moles of water can be formed from 1.1 moles of CH4?
(3.1 x 10^3) (1.00 x 10^7) =
Answer:
(3.1 x 10^3) (1.00 x 10^7) = 31000000000
please help me :( What is the correct ratio of carbon to hydrogen to oxygen in glucose (C6H120.)?
12:12:6
01:2:1
02:1:1
6:6:12
Answer:
Either 12:12:6 or 6:6:12
Explanation:
If I remember correctly the answer should be 6:6:12
The melting and boiling points of a group of elements decrease as you go down the group, while their reactivity increases.
a.. Are the elements from the first group or the second last group of the Periodic Table?
b ..Does this group consist of metals, metalloids, non-metals or a mix?
c.. Identify two elements in this group.
Answer:
a) first group
b) metals
c) K - potassium, Li - lithium
Explanation:
a) they are the alkali metals
b) they're alkali metals lol
c) just look at a periodic table :P
in what and what no energy is used?
Answer:
Energy is used when someone is climbing while energy is not used when someone is going down the slope
Calcium reacts with oxygen to make calcium oxide, CaO. What is the theoretical yield (g) of CaO(s) that could be prepared from 7.75 g of Ca(s) and 2.44 g of O2(g)
Answer:
Explanation:
2Ca + O₂ = 2CaO
80 g 32 g 112 g
given amount of Ca = 7.75 g
it will require oxygen = 32 x 7.75 / 80 = 3.1 g
but available oxygen = 2.44 so oxygen is the limiting reagent .
32g oxygen reacts with calcium to give 112 g of calcium oxide
2.44 gram of oxygen reacts with calcium to give 112 x 2.44 / 32 of CaO .
= 8.54 gram .
Theoretical yield of CaO = 8.54 gram.
Scientific knowledge is open to change as new information is discovered. Which of the following would NOT be a result of new scientific knowledge?
A
Scientists discover that a type of fungus on this log does not require oxygen for absorption and change the classification system.
B
Scientists publish an article that mentions the historic decline in the population of blue stain fungi.
C
Scientists classify a recently discovered bacterium living on this log using generally accepted naming procedures.
D
Scientists discover a bacterium living on this log that is multicellular and revise their classification
Right amount of gravity
the answer is: 9.80665
Need help ASAP..... (0.567 liters of H2O is how many moles of H2O? HINT: 1 mL H20 = 1 gram
H20)
Answer:
31.5 moles
Explanation:
Volume of H2O = 0.567 L
Number of mole of H2O =.?
Next, we shall convert 0.567 L to millilitres (mL). This can be obtained as follow:
1 L = 1000 mL
Therefore,
0.567 L = 0.567 L × 1000 mL / 1 L
0.567 L = 567 mL
Thus, 0.567 L is equivalent to 567 mL.
Next, we shall convert 567 mL to grams (g). This can be obtained as follow:
1 mL of H2O = 1 g
Therefore
567 mL of H2O = 567 g of H2O
Finally, we shall determine the number of mole in 567 g of H2O. This can be obtained as follow:
Mass of H2O = 567 g
Molar mass of H2O = (2×1) + 16
= 2 + 16 = 18 g/mol
Mole of H2O =?
Mole = mass /Molar mass
Mole of H2O = 567 /18
Mole of H2O = 31.5 moles
solve this very easy choose option fast
Answer:
i think its alcohol and salt because they put salt on the ground to dissolve the snow so what I think is its alcohol and salt cuz they both look like they would evaporate pretty easy and alcohol evaporates really really easy so I think it's alcohol and salt because salt May absorb it or something I don't know but yeah
Answer: alcohol and iodide
Explanation:
Meaning of biocentric
can i please get brainlyest
"the view or belief that the rights and needs of humans are not more important than those of other living things."
Answer:
the view or belief that the rights and needs of humans are not more important than those of other living things.
explanation:
How do elements tend to structure the molecules of life?
Answer:
The six most common elements in living things are carbon, hydrogen, oxygen, nitrogen, phosphorus, and sulfur. Atoms of these elements combine and form thousands of large molecules. These large molecules make up the structures of cells and carry out many processes essential to life.
Explanation:
hope that helped
Different elements combine together to form an organism and other essential organic and inorganic molecules for the life and survival of organisms.
In multicellular organisms, such as animals, atoms form molecules by coming together. These atoms are present in the elements. Molecules can interact to form cells. Cells combine to form tissues, which make up organs.
At the most basic level, all organisms are made of a combination of elements:
carbon is the most common and essential element for the lifeCarbon has the ability to form a wide range of compounds.With other elements most commonly, hydrogen, the oxygen they form various molecules such as carbohydrates, lipids, and many more.With other molecules like phosphate, sulfur, and nitrogen they make essential macromolecules and nutrients like protein, vitamin, and nucleic acid essential for life.Thus, Different elements combine together to form an organism and other essential organic and inorganic molecules for the life and survival of organisms.
Learn more about elements:
https://brainly.com/question/13025901
What is the molecular geometry of the atoms bonded to the carbon atom indicated with arrow I in this structure of caffeine?
Answer:
Trigonal planar
Explanation:
If we look at the carbon atom indicated I in the image, we will discover that it is a carbon atom that is bonded to a nitrogen atom via a double bond.
Recall that an sp2 hybridized carbon atom has a trigonal planar geometry. When a carbon atom is sp2 hybridized, it is in a trigonal planar geometry as we can clearly see from the image.
the kinetic molecules theory helps explain relastionships between
Answer:
hi :D
Explanation:
State the relationship between temperature and kinetic energy. The Kinetic Molecular Theory allows us to explain the existence of the three phases of matter: solid, liquid, and gas. In addition, it helps explain the physical characteristics of each phase and how phases change from one to another.
hope this helps
._.
...
how much valence electrons does aluminum have
Answer:
3
Explanation:
It is in the third column or group on the periodic table
group of students is investigating whether the force of friction depends on the nature of the surfaces in contact. The students push two pieces of wood each with the same force on a table. One piece of wood is smooth and the other is rough. The distance traveled by each piece of wood is shown.
Experimental Observations
Student 1 Student 2 Student 3 Student 4
Distance traveled by smooth piece of wood 20 cm 18 cm 16 cm 19 cm
Distance traveled by rough piece of wood 15 cm 12 cm 10 cm 11 cm
What was the outcome variable (dependent variable) in this experiment?
Group of answer choices
Distance traveled
Smooth wood
Rough wood
Number of students
Answer:
Distance traveled.
Answer: distance traveled
Explanation: I just got the answer right.
2.
_______ properties depend on the amount of
matter present
Answer:
extensive properties
Explanation:
,such as mass and volume, depend on the amount of matter being measured. Intensive properties, such as density and color, do not depend on the amount of the substance present. Physical properties can be measured without changing a substance's chemical identity.
Question 20 of 66
Which of the following species has the same number of protons as Fe3+?
A) Mn3+
B) Co2+
C) Fe2+
D) Nit
E) CO3+
Fe²⁺ has the same number of protons as Fe³⁺.
In order to know the number of protons of a species, we need to look for the atomic number (Z) in the Periodic Table.
The atomic number of Fe is 26, so it has 26 protons. Since protons are in the nucleus, they are not lost nor gained. Fe³⁺ results from Fe losing 3 electrons, but it has 26 protons as well.
Taking this into account, let's consider the number of protons of the following species:
A) Mn³⁺. It has 25 protons like Mn (Z = 25).
B) Co²⁺. It has 27 protons like Co (Z = 27).
C) Fe²⁺. It has 26 protons like Fe (Z = 26).
D) Ni. It has 28 protons (Z = 28).
E) Co³⁺. It has 27 protons like Co (Z = 27).
Fe²⁺ has the same number of protons as Fe³⁺.
You can learn more about atomic number here: https://brainly.com/question/17274608?referrer=searchResults
calculate the molarity of a solution made by dissolving 3.7 moles of sodium chloride in 8.7 liters of water?
Answer:
Molarity = 0.425 M
Explanation:
Given data:
Number of moles = 3.7 mol
Volume of solution = 8.7 L
Molarity of solution = ?
Solution:
Molarity is used to describe the concentration of solution. It tells how many moles are dissolve in per litter of solution.
Formula:
Molarity = number of moles of solute / L of solution
Molarity = 3.7 mol/8.7 L
Molarity = 0.425 M
Sodium chloride can be used to preserve meat because
Answer:
Salt is effective as a preservative because it reduces the water activity of foods. .
Which of these are trends of elements as you go down a group?
a.. The atomic number increases.
b ...The number of electrons in the outermost shell increases.
c ...The number of filled electron shells increases.
d...The mass and size of the atoms increase
e...The elements change from being metallic to non-metallic.
Answer:
c. the number of filled electrons shells increases
Answer:
the answer is c
Read the statement below and decide if it represents physical change or chamical change.
Iron is heated, causing it to melt.
O Physical Change
Chemical Change