Answer:
Karenia brevis produces toxins called brevetoxins that affect a variety of marine wildlife. Aquatic organisms can be exposed to brevetoxins in several ways: coming into contact with K. brevis cells or toxins in the water, ingesting cells, inhaling toxins and consuming toxic prey.
Explanation:
Which process directly moves nutrients from animals to the air?
D.Breathing
Oxygen obtained through respiration is used by cells in the cellular respiration process to obtain energy. Each animal has a different way of performing gas exchange, but we can say that it is through breathing that all animals move nutrients directly into the air through breathing
-
In the reaction: 2X2Y3 + 3Z(QR)4 4X(QR)3 + 3ZY2
What is the charge of the "X" cation needed to form these compounds?
Answer:
That's simple it's the caca of 54 32 x (5) b ÷ 5683jvl done so your answer is 0
Choose the aqueous solution below with the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable.
The question is incomplete, the complete question is;
Choose the aqueous solution that has the highest boiling point. These are all solutions of nonvolatile solutes and you should assume ideal van't Hoff factors where applicable. 0.100 m C6H12O6 0.100 m AlCl3 0.100 m NaCl 0.100 m MgCl2 They all have the same boiling point.
Answer:
AlCl3 0.100 m
Explanation:
Let us remember that the boiling point elevation is given by;
ΔTb = Kb m i
Where;
ΔTb = boiling point elevation
Kb = boiling point constant
m = molality of the solution
i = Van't Hoff factor
We can see from the question that all the solutions possess the same molality, ΔTb now depends on the value of the Van't Hoff factor which in turn depends on the number of particles in solution.
AlCl3 yields four particles in solution, hence ΔTb is highest for AlCl3 . The solution having the highest value of ΔTb also has the highest boiling point.
Expressed to the correct number of significant figures, the sum of two masses is 445.2 grams. Which two masses produce this answer?
a) 210.10g+ 235.00g
b) 210.100g + 235.10g
c) 210.1g + 235.1g
d) 210.10g + 235.10g
Answer:
All except a
Explanation: I like math. Pls mark brainliest.
The two numbers presented in the options, B, C, and D give a sum of 445.2 grams. So the correct options are B, C, and D.
What are significant figures?The number that is given as digits is established using significant figures. A significant depiction of numbers is carried by these digits. Frequently, significant numbers are employed in place of figures. By counting all of the values beginning with the first non-zero digit on the left, we may determine the number of significant digits. 13.56, for instance, has four significant digits.
The crucial or key digits that accurately represent the meaning of a certain number are known as the significant figures of that number. 7.864 contains four significant digits, for instance. These huge amounts give the accuracy of the numbers. Additionally, they are known as important digits.
Therefore, the correct options are B, C, and D.
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Please help: A complete moon cycle is how many weeks
Answer:
29.5 days
Explanation:
its 29.5 days i hope it helps
Answer:
The Moon takes 27.3 days to orbit Earth, but the lunar phase cycle (from new Moon to new Moon) is 29.5 day
Which changes would cause an increase in the resistance of a wire? Check all that apply.
increasing its temperature
decreasing its temperature
using a longer wire
using a shorter wire
m using a thicker wire
using a thinner wire
Answer:
Increasing its temperature.
Longer
and thinner
Explanation:
e2021
The resistance of a wire increases by increasing its temperature, using a longer wire and using a thinner wire.
Resistivity of a wireThe resistivity of wire describes the opposition to the flow of current in the wire.
[tex]R = \frac{\rho L}{A} \\\\\rho = \frac{RA}{L} \ (ohm-meter)[/tex]
where;
R is the resistance (ohms)ρ is resistivity of the wire (ohm-meter)L is length of the wire (m)A is area of the wire (m²)From the formula above, the resistance of a wire increases with
increase in the length of the wiredecrease in thickness (radius) of the wireincrease in temperatureLearn more about resistance of a wire here: https://brainly.com/question/469388
Models can be used to make predictions .
truth or false ?
Answer:
true
...................
84.9 g of solid iron reacts with oxygen gas forming iron(III) oxide. How many moles of oxygen will react
Answer:
1.14 moles of oxygen will react
Explanation:
The balanced equation of reaction between iron and oxygen is
4 Fe + 3 O₂ → 2 Fe₂O₃
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), the following amounts of each compound participate in the reaction:
Fe: 4 molesO₂: 3 molesFe₂O₃: 2 molesThe molar mass of iron being Fe 55.85 g/mole, then the following amount of mass reacts by stoichiometry: 4 moles* 55.85 g/mole=223.4 g
You can apply the following rule of three: if by stoichiometry 223.4 grams of Fe react with 3 moles of O₂, 84.9 grams of Fe react with how many moles of O₂?
[tex]moles of O_{2} =\frac{84.9 grams of Fe*3 moles ofO_{2} }{223.4 grams of Fe}[/tex]
moles of O₂= 1.14 moles
1.14 moles of oxygen will react
Dona is attempting to make an electromagnetic to pick up old nails in her driveway. Which of these materials would be best to us for the core to make the strongest electromagnetic to pick up the most nails?
Answer:
The materials would be best to us for the core to make the strongest electromagnetic to pick up the most nails is described below in detail.
Explanation:
Use a couple of wire strip-pers to exclude some centimeters of insulation from every end of the cable. Skillfully cover the cable around the nail. The more cable you enclose around the nail, the more effective your electromagnet will be. Compose certain that you leave sufficient of the cable unwrapped so that you can connect the battery.
1. Which word has the same phoneme as grew, rude, and truth?
A. thumb
B. sure
C. look
D. scoot
Answer:
B-Sorry if this isn't right :/ Good luck.
Explanation:
Answer:
D. Scoot
Explanation:
Grew, Rude and truth all have the sound /OO/ scoot follows that pattern.
what is used to make the dry cells ????
Answer: The parts of a dry cell battery are as follows: at the center is a carbon rod called a cathode. The cathode is surrounded by an electrolyte paste. The paste and cathode are surrounded by a separator before finally being sealed within a zinc cylinder.
Explanation: A diagram is show below
magnesium__ + sulfuric acid goes to form magnesium sulfate+ water + carbon dioxide
Answer:
carbonate
Explanation:
this is because when carbonates react with acid they form carbon dioxide and water and respective metal oxide
1. Which of the following seismic waves is detected first by the seismograph?
A L-waves B P-waves
CR-waves D.S-waves
Answer:
AL- waves
Explanation:
because it is famousable
The water cycle describes the movement of water on Earth. Water in oceans and lakes evaporates and turns into water vapor. This water vapor condenses and forms clouds which produce precipitation. Precipitation falls all over the Earth's surface. The water eventually comes back to the oceans through run-off. Which steps in the water cycle carry water out of an ocean and into a freshwater lake?
A. Evaporation and precipitation
B. Rivers and streams
C. Underground tunnels
D. Condensation and run-off
Answer:
c. Underground tunnels
Explanation:
Yes, water below your feet is moving all the time, but, no, if you have heard there are rivers flowing below ground, that is not true. Water moves underground downward and sideways, in great quantities, due to gravity and pressure. Eventually it emerges back to the land surface, into rivers, and into the oceans to keep the water cycle going.
Note: This section of the Water Science School discusses the Earth's "natural" water cycle without human interference.
The steps in the water cycle that carries water out of the ocean into a freshwater lake are rivers and streams.
What is the water cycle?The water cycle is used to describe the movement of water in the ecosystem. It involves the various processes through which water can move in the universe.
The steps in the water cycle that carries water out of the ocean into a freshwater lake are rivers and streams.
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Which of these is a biotic factor of an ecosystem?
A) Crystals of salt
B) Rays of sunlight
C) Grains of Sand
D) Strands of seaweed
Determine if you can swim in 1×10^27 molecules of water
How many grams of magnesium oxide would be produced if 3.8 grams of magnesium reacted completely with 2.1 grams of oxygen
Answer:
5.3g of MgO would be produced
Explanation:
Based on the chemical reaction:
2Mg(s) + O₂(g) → 2MgO(s)
1 mole of Mg reacts per mole of oxygen.
To solve this question we need to convert the mass of each reactant to moles in order to find limiting reactant using the chemical equation:
Moles Mg -Molar mass: 24.305g/mol-:
3.8g Mg * (1mol / 24.305g) = 0.1563moles Mg
Moles O₂ -Molar mass: 32g/mol-:
2.1g O₂ * (1mol / 32g) = 0.0656 moles O₂
For a complete reaction of 0.0656 moles of O₂ are required:
0.0656 moles O₂ * (2 mol Mg / 1mol O₂) = 0.132 moles Mg
As there are 0.1563 moles of Mg, Mg is the excess reactant and O₂ the limiting reactant.
0.0656 moles O₂ produce:
0.0656 moles O₂ * (2 mol MgO / 1mol O₂) = 0.132 moles MgO
The mass is -Molar mass MgO: 40.3g/mol-:
0.132 moles MgO * (40.3g / mol) =
5.3g of MgO would be produced
How many atoms are in 11.5 g of Hg?
A. 5.73 x 10^-2 atoms
B.3.45 atoms
C.3.45 x 10^22 atoms
D. 5.73 atoms
4.Which scientist described the electrons as traveling in certain orbits or energy levels?
a.Dalton
b.Rutherford
c.Thomson
d.Bohr
5.In a famous experiment, scientists bombarded a very thin gold (Au) foil with positively charged alpha particles. They found that most of the alpha particles passed right through the Au foil. However, a few of the alpha particles were deflected or bounced back toward the source. How did these scientists explain their results?
a.Negative charges are spread throughout the atom.
b.Negative charges are located in the tiny nucleus of the atom.
c.Positive charges are located in the tiny nucleus of the atom.
d.Positive charges are spread throughout the atom.
6.The atomic mass represents the weighted average of an element’s
a.Ions
b.mass numbers
c.atomic numbers
d.isotopes
7.The number of protons is represented by the element’s
a.atomic number
b.mass number
c.atomic mass
d.isotope
8.The number of protons plus neutrons is represented by the
a.atomic number
b.mass number
c.atomic mass
d.isotope
9.How many valence electrons would an atom of Chlorine have?
a.2
b.3
c.7
d.8
10.An element is found to have 2 electrons in the 3rd energy level. What is this element?
a.Boron
b.Magnesium
c.Fluorine
d.Argon
11.Which shows the order of decreasing atomic size?
a.Si, Al, Mg, Na
b.I, Br, Cl, F
c.Be, Mg, Ca, Sr
d.C, P, Se, I
12.Which of the following elements has the highest ionization energy and why?
a.Argon because it has more protons in the nucleus.
b.Argon because it has a full valence shell.
c.Chlorine because it only needs one valence electron to fill its valence shell.
d.Chlorine because it attracts electrons better.
13.Which shows the order of increasing ionization energy?
a.Si, Al, Mg, Na
b.Ga, Ge, As, Se
c.Be, Mg, Ca, Sr
d.F, Cl, Br, I
14.Identify the reason why atoms decrease in size(atomic radius)across a period on the Periodic Table.
a.Gravity pulls the electrons in towards the nucleus.
b.Increase in energy levels increases the attraction and thus pulls electron cloud in.
c.Increasing strong positive nuclear charge from the nucleus pulls in the negative electron clouds and increases with the increase in protons and electrons.
d.Electrons lose energy and collapse with an increasing number of electrons and protons.
15.What is the shielding effect?
a.The neutrons shield protons from the attraction of the electrons from the first energy level.
b.Valence electrons are shared equally between atoms.
c.The repulsion of electrons in the same energy level.
d.The inner-core electrons shield outer-core electrons from the attraction to the atom’s nucleus.
16.Which statement is an accurate description of elements from Period 3 on the periodic table?
a.It contains elements with the same number of 3 protons.
b.It contains elements with the same number of3valence electrons.
c.It contains elements with the outermost protons in the same 3rd energy level.
d.It contains elements with the outermost electrons in the same 3rd energy level.
17.The column that an element is located in tells us
a.the total number of valence electrons an atom has.
b.the total number of energy levels an atom of that element has.
c.the highest energy level an atom of that element has.
d.both b & c.
18.The Halogen family of elements all have 7 valence electrons. Which column would they be in?
a.01 (IA)
b.02 (IIA)
c.4 (IVA) or 14
d.7 (VIIA) or 17
19.The Alkali and Alkaline Earth metals belong to which columns, respectively?
a.Column IA & IIA
b.Column VIIA & Column VIIIA
c.Column IIIA & IVA
20.What do carbon and silicon have in common?
a.They belong to the same column (family), therefore they have the same number of valence electrons.
b.They belong to the same column (family), therefore they have the same number of total electrons.
c.They belong to the same column (family), therefore they have the same number of energy levels.
d.They belong to the same column (family), therefore they have the same number of protons.
21.Electromagnetic radiation can take the form of which of the following types of waves
a.Heat
b.Light
c.Ultraviolet
d.All of the above
24.In order to go to a lower energy orbit, an electron
a.Must disappear
b.Must combine with other electrons
c.Lose energy of a specific amount
d.Must be transferred to another atom
25.Please choose the correct sequence that describes the excitement of an atom.
1. Such an electron transition raises the atom from the ground state to the excited state.
2. When energy is added to an atom from an outside source, its electrons move to a higher energy level (orbit)
3. As a result, the atom emits a photon.
4. When the atom is in an excited state, the electron can drop from the higher energy level to a lower energy level.
a.1, 2, 3, 4
b.4, 3, 2, 1
c.2, 1, 4, 3
d.3, 4, 1, 2
the empirical formula is C6H6O.vapour density is 47.find the molecular formula
Answer: The molecular formula will be [tex]C_6H_6O[/tex]
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
The empirical formula is [tex]C_6H_6O[/tex]
The empirical weight of [tex]C_6H_6O[/tex] = 6(12)+6(1)+1(16) = 94 g.
The molecular weight = [tex]2\times \text{vapour density}=2\times 47=94[/tex]
Now we have to calculate the molecular formula.
[tex]n=\frac{\text{Molecular weight}}{\text{Equivalent weight}}=\frac{94}{94}=1[/tex]
The molecular formula will be=[tex]1\times C_6H_6O=C_6H_6O[/tex]
explain the factor of a skeleton system
Plz help
What does the acid test tell you about a mineral?
A. Whether it is a carbonate
B. whether it is organic
C. Whether it is man-made or natural
D. Whether it is a silicate
Science A P E X
How do magnets move objects?
Answer: Magnets have a force which is known as no contact force. This force tries to attract the metallic objects near it, which makes it move.
Explanation:
How do you think the artist creates sculptures that vary in color and intensity?
Answer:
Light reflected off objects. Color has three main characteristics: hue (red, green, blue, etc.), value (how light or dark it is), and intensity (how bright or dull it is). Colors can be described as warm (red, yellow) or cool (blue, gray), depending on which end of the color spectrum they fall.
Christ Crowned / Honthorst
Christ Crowned with Thorns, Gerrit van Honthorst, about 1620
Value describes the brightness of color. Artists use color value to create different moods. Dark colors in a composition suggest a lack of light, as in a night or interior scene. Dark colors can often convey a sense of mystery or foreboding.
Light colors often describe a light source or light reflected within the composition. In this painting, the dark colors suggest a night or interior scene. The artist used light colors to describe the light created by the candle flame.
Annunciation / Bouts
The Annunciation, Dieric Bouts, 1450–1455
Intensity describes the purity or strength of a color. Bright colors are undiluted and are often associated with positive energy and heightened emotions. Dull colors have been diluted by mixing with other colors and create a sedate or serious mood. In this image the artist captured both the seriousness and the joy of the scene with the dull gray stone interior and the bright red drapery.
Explanation:
Write the formula and determine the percent by mass of the salt in barium hydroxide octahydrate *
(show work)
Answer:
315.51g/mol
Explanation:
137(33 + (16.00 + 1.01) 2 + 8 [1.01 (2) + 16.00] = 315.51g/mol
HELP ASAP GIVING BRAINLIEST FIVE STARS AND HEART!
Answer with at least 5 sentences in your own words:
What are two properties of electromagnetic radiation?
Answer: In empty space, electromagnetic radiation will fly. Some kind of material must pass across most other forms of waves. In order to be heard, for instance, sound waves require either a gas, solid, or liquid to travel through.
14. How many liters would 5 moles of oxygen gas take up?
a.0.22L
b.112
c.27.4L
d.55L
Answer:
a 0.22L
Explanation:
Answer:
A
Explanation:
1 moles of oxygen is 0.044L
Petroleum is a mixture of many alkanes. The alkanes are separated and purified at oil refineries. What process decribes what happens in an oil refinery?
Answer:
Fractional distillation
Explanation:
The process of separating petroleum products into its fractions is called fractional distillation.
Fractional distillation is a method of separating a mixture of substances based on the differences in their boiling points.
Petroleum is a mixture of hydrocarbons separated in a large fractionation tower having many trays maintained at different temperatures.
As the vapor containing the petroleum mixture ascends the fractionation tower, the mixture is separated at each tray to yield the various fractions of petroleum.
how much empty space was there in the medium-sized rock sample
Answer:
I'm assuming this is from a lab that you did - in which case, I can't really help you out here.
Explanation:
Is barium hydroxide Ba(OH)2 or is BaOH?
Answer:
What is the charge on the barium ion and what is the charge of the hydroxide ion.
Explanation:
To get the correct formula they have to add to zero over all.
