Since, the options have not been given the question is incomplete.
What is Darwin's name for species that do not appear to have changed for millions of years?
a.
Dinosaurs
b.
Living fossils
c.
Old souls
d.
Ancient moderns
Answer: b. Living fossil
Explanation:
In 1859 Charles Darwin proposed the term living fossil, that means a species or group of species that had not changed in terms of evolutionary context thus can be useful in tracing the extinct or previously existing forms of life. The examples of the living fossils are horseshoe crabs, ginkgo (Conifers) and tuatara. These group of animals were existed unchanged in the Ordovician, Permian, and Triassic periods respectively with few surviving species.
Answer:
the answer is living fossils so it would be b
Explanation:
how do i know i took the test
Which two forces keep the planets
and moons in their orbits?
Answer:
“Without gravity, the planets' inertia would keep them moving in straight lines. Gravity “steers” the planets in their oval paths around the Sun. Together, gravity and inertia keep the planets in their orbits.”
Explanation:
BRAINLIEST PLZZZ
Decide which element probably forms a compound with hydrogen that has a chemical formula most and least similar to the chemical formula of the compound formed by hydrogen and sulfur.
Answer:
Most similar- oxygen
Least similar- sodium
Explanation:
The complete question is shown in the image attached.
Now let us consider all the options in the questions carefully. We do know that hydrogen forms covalent bonds with sulphur. Two hydrogen atoms form form two polar covalent bonds with one sulphur atom. The molecule is bent owing to the presence of two lone pairs of electrons on the sulphur central atom.
Oxygen is in the same group as sulphur in the periodic table. The compound between hydrogen and sulphur is strikingly similar to the compound formed between sulphur and hydrogen due to chemical similarity of compounds of elements in the same group of the periodic table. Hence H2O bears the greatest similarity to H2S.
The bond between hydrogen and halogens is also polar covalent but less similar to the bond between sulphur and hydrogen.
Lastly, the bond between hydrogen and sodium is ionic and least similar to the bond between hydrogen and sulpur. We actually have in that compound, Na^+ H^-. Sodium transfers one electron to hydrogen as is implied in the ionic formula shown.
Hence the answer above.
THE WEATHER BALLOON DATA WE STUDIED WAS MEASURED AND RECORDED AT MIDNIGHT. THE TEMPERATURE OF THE AIR AT Earth's SURFACE IS DIFFERENT DURING DIFFERENT TIME OF THE DAY. WHAT OTHER TIMES OF THE DAY COULD WE MEASURE THE SURFACE TEMPERATURES OUTSIDE THE SCHOOL BUILDING? WHY? Write your thought on a sticky note and add it to our board. (Please initial your note.)
Answer night
Explanation:
because day is to hot
CALCULATOR
COLOR THEME
D) SPEAK OPTIONS
ZOOM
Do) 17. A compound containins 27.3 grams of carbon and 72.7 grams of oxygen. Which
of the following is a possible molecular formula?
D
CLE
Answer: The possible molecular formula will be [tex]CO_2[/tex]
Explanation:
Mass of C= 27.3 g
Mass of O = 72.7 g
Step 1 : convert given masses into moles.
Moles of C =[tex]\frac{\text{ given mass of C}}{\text{ molar mass of C}}= \frac{27.3g}{12g/mole}=2.275moles[/tex]
Moles of O =[tex]\frac{\text{ given mass of O}}{\text{ molar mass of O}}= \frac{72.7g}{16g/mole}=4.544moles[/tex]
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C = [tex]\frac{2.275}{2.275}=1[/tex]
For O =[tex]\frac{4.544}{2.275}=2[/tex]
The ratio of C : O = 1: 2
Hence the empirical formula is [tex]CO_2[/tex]
The possible molecular formula will be=[tex]n\times CO_2[/tex]
What carpet Burns in a deficiency of O2 a mixture of CO and CO2 forms.Carbon Burns in excess O2 to form only CO2 and CO Burns in excess O2 to form only CO2. Calculate ΔH for C(graphite +1/2O2) →CO(g).
Answer:
Explanation:
From the combustion of carbon, the reactions occurring in limited oxygen conditions are:
[tex]C(graphite) + \dfrac{1}{2}O_{2(g)} \to CO_{(g)}[/tex]
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex]
If it occurs in excess, then any leftover CO changes to CO2. i.e.
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)}[/tex] ---- (1)
[tex]CO_{(g)} + \dfrac{1}{2}O_{(g)} \to CO_{2(g)}[/tex] ----- (2)
From (1), the enthalpy change is:
[tex]\Delta H_{rxn1} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{f C(graphite)}+ \Delta H^0_{fCO_2(g)}[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol -(0+0)[/tex]
[tex]\Delta H_{rxn1} =-393.5 \ kJ/mol[/tex]
From (2), the enthalpy change is:
[tex]\Delta_{rxn2} = \Delta H^0_{fCO_2(g)} - ( \Delta H^0_{fCO(g)} + \dfrac{1}{2} \Delta H^0_{fO_2(g)})[/tex]
[tex]\Delta_{rxn2} = -393.5 \ kJ/mol -(-110.5 + \dfrac{1}{2}(0))[/tex]
[tex]\Delta_{rxn2} = -283.0 \ kJ/mol[/tex]
Subtracting (2) from (1), we get:
[tex]C(graphite) + O_{2(g)} \to CO_{2(g)} \ \ \ \Delta H_{rxn} = -393.5 \ kJ/mol}[/tex]
[tex]CO_{(g)} + \dfrac{1}{2} O_2(g) \to CO_{2(g)}} \ \ \ \Delta H _{rxn2} = -283.0 \ kJ/mol[/tex]
[tex]C(graphite) + O_{2(g)} \to CO (g) + \dfrac{1}{2}O_{2(g)} \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
[tex]C(graphite) + \dfrac{1}{2} O_{2(g)} \to CO (g) \ \ \ \Delta H_{rxn} = -110.5 \ kJ/mol[/tex]
The enthalpy change ΔH of the reaction = -110.5 kJ/mol
If 4.55 moles of hydrogen were reacted with excess nitrogenin the equations N2 + 3 H2 = 2 NH3 and 48.7 g of ammonia product was recovered what would be the percent yield of the reaction?
Answer:
Percent yield = 94.5%
Explanation:
Given data:
Number of moles of hydrogen = 4.55 mol
Mass of ammonia recovered = 48.7 g
Percent yield of ammonia = ?
Solution:
Chemical equation:
N₂+ 3H₂ → 2NH₃
Now we will compare the moles of ammonia and hydrogen.
H₂ : NH₃
3 : 2
4.55 : 2/3×4.55 = 3.03 mol
Theoretical yield of ammonia:
Mass = number of moles × molar mass
Mass = 3.03 mol × 17 g/mol
Mass = 51.51 g
Percent yield:
Percent yield = ( actual yield / theoretical yield ) × 100
Percent yield = (48.7 g/ 51.51 g) × 100
Percent yield = 0.945 × 100
Percent yield = 94.5%
If one force on an object is 5 N upward and the other is 10 N downward what is the objects motion?
To solve this we must be knowing each and every concept related to force. Therefore, the objects motion will be towards downward with a force of 5 N.
What is force?A force is an outside entity that has the power to alter a body's state of rest or motion. It has a direction and a magnitude. The point where forces are applied is determined by the the force's direction as well as the application of the force.
Newton and dyne units are used to measure the force exerted on an item. When using the centimeter kilogram second system of units, force is measured in dynes (CGS unit). In the common international system of units, it is denoted by the letter Newton (N) (SI unit).
upward force=5 N
downward force= 10 N
total force acting on body=downward force-upward force
= 10 N - 5 N
=5 N downward force
The objects motion will be towards downward with a force of 5 N.
Therefore, the objects motion will be towards downward with a force of 5 N.
To learn more about force, here:
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When salt water is heated leaving behind solid salt, this is separating a mixture by what method ?
find the weight of HNO_3 present in 20ml, 0.30 N
Answer:
mass of HNO₃ = 0.378 g
Explanation:
Normality = Molarity * number of equivalents
Molarity = Normality/number of equivalents
normality of HNO₃ = 0.30 N, Volume = 20 mL
HNO₃ ionizes in the following way:
HNO₃(aq) ----> H⁺ + NO₃⁻
Therefore, number of equivalents for HNO₃ is 1
molarity of HNO₃ = 0.30/1 =0.30 mol/dm³
Using the formula, molarity = number of moles/volume in liters
number of moles = molarity * volume
Number of moles of HNO₃ = 0.30 mol/dm³ * 20ml * 1 dm³ /1000 mL
number of moles = 0.006 moles
From the formula, mass = number of moles * molar mass
molar mass of HNO₃ = 63.0 g/mol
mass = 0.006 * 63
mass of HNO₃ = 0.378 g
Which of the following is true about the climate of Anchorage?
The winters are cold and snowy.
The snow was piled next to the landing strip.
It was 27°F.
Summers are cold in Anchorage.
Answer:
A
Explanation:
Which of the following monosaccharides is not an aldose?
Select one:
a, erythrose
b. fructose
c. glucose
d. glyceraldehyde
Answer:
fructose
Explanation:
because fructose is a ketonic sugar.
What ara the differences between the homolytic and heterolytic bond dissociation ? And why homolytic dissociation energy of H-H (104 KJ/mol) is lower than its heterolytic bond dissociation energy (401 KJ/mol)?
Answer:
Following are the difference in homolytic and hetrolytic bond dissociation.
Homolytic dissociation is referred as the amount of energy released during homolytic fission. Homolytic fission is known as the dissociation of chemical bond in two equal fragmentswhereas, Hetrolytic dissociation is referred as the amount of energy released during Hetrolytic fission. Hetrolytic fission is known as the dissociation of chemical bond in two unequal fragments.Homolytic fission gives one electron each to its fragments whereas Hetrolytic fissiongives two electron to one fragment and zero electron to other fragment.Energy released during Homolytic fission is lower than the Hetrolytic fission as the electron distribution to its fragments is uniform in homolytic whereas electron distribution to its fragments is uniform in hetrolytic fission.
Thus bonds form in hetrolytic fission is more stronger than the the bonds formed in homolytic fission.
Hence, more energy is required to break the bonds of hetrolytic fission as compared to homolytic fission
Thus, homolytic dissociation energy of H-H (104 KJ/mol) is lower than its heterolytic bond dissociation energy (401 KJ/mol)
What Is an example of weather?
A. The average rainfall in Arizona over the pervious three months
B. The increase in temperature over North America over the past decade
C. The time for high tide in Daytona Beach today
D. The temperature and wind speed in Philadelphia today
Select the correct answer.
Which of these activities increases the amount of carbon in the atmosphere?
O A.
animals eating plants
OB. burning of fossil fuels
OC. fossilization
O D.
photosynthesis
Mention any two factors that determines Cis/Trans Isomerization
Answer:
1. There most not be rotation within the molecule.
2. Two non identical group must be present in the double bonded carbon atom.
Explanation:
This is because cis/ trans isomerism are that exhibit different structural configurations where the atoms are spartially arranged. They are also refered to as geometric isomers. They cannot be interconverted at room temperature because it requires the bonds to be broken and restructured.
Cis shows that the functional groups on present in the same side which trans isomerism show that the functional groups are on opposite sides.
b. Which two neutral elements have different numbers of protons but similar properties?
Answer:
Helium and neon
Explanation:
A 4.0g Glass was heated from 5°C to 45°C after absorbing 32 J of heat. What is the specific heat of the glass? 
Answer:
[tex]c=0.2\ J/g^{\circ} C[/tex]
Explanation:
Given that,
Mass of a glass, m = 4 g
Initial temperature, [tex]T_i=5^{\circ} C[/tex]
Final temperature, [tex]T_f=45^{\circ} C[/tex]
Heat absorbed, Q = 32 J
We need to find the specific heat of the glass. The formula for the heat absorbed is given by :
[tex]Q=mc\Delta T\\\\c=\dfrac{Q}{m\Delta T}\\\\c=\dfrac{32\ J}{4\ g\times (45-5)^{\circ} C}\\\\=0.2\ J/g^{\circ} C[/tex]
So, the required specific heat of the glass is [tex]0.2\ J/g^{\circ} C[/tex].
How are food webs and food chains related? HELP IF YOU WANT BRAINLEIST!!
Food webs only contain consumers.
Food webs consist of only one food chain.
Food webs are made of many food chains.
Food webs only contain producers.
Answer: Food webs are made of many food chains is the answer.
Explanation:
Food web consists many food chains.
Which of the following would be most likely to experience strong intermolecular forces?
A. Molecules that contain no electrically charged regions.
B. Molecules that contain atoms of oxygen.
C. Molecules that are composed of solely ions.
D. Molecules that have both negatively and positively charged parts.
Answer:
The correct answer is D
Explanation:
Just took quiz
8. As the temperature of a mixture increases, one part of the mixture may 2 points
melt while the other parts remain solid. *
True
Or
False
Answer:
It's false
Explanation:
Mixtures are always combinations of the same compounds that are at different states.
Match the word with the definition. Write the correct letter in the space
provided. Reminder
that your answers should be blue.
A. Proton
B. Periodic Table
C. Atom
D. Chemical Symbol
E. Group
F. Atomic Number
G. Atomic Mass
H. Period
1. Electron
J. Neutron
K. Nucleus
1. Average mass of all the isotopes of that element
2. Series of elements arranged in rows on the periodic table
3 Smallest particle that still can be considered an element
4. Subatomic particle with no charge
5. An abbreviation of an element's name, usually one or two letters
6. Subatomic particles with a positive charge
7.
A small region in the center of an atom
8.
Arrangement of elements showing repeating pattern of their
properties
9. Series of elements arranged in columns on the periodic table
10.
Subatomic particles with a negative charge
11.
Number of protons in the nucleus of an atom
Answer:
this may be wrong and if it is im sorry
A=6
B=8
C=3
D=5
E=9
F=11
G=1
H=2
I=10
J=4
K=7
What is the region of a longitudinal wave where particles are closest together called?
Answer:
compressions
Explanation:
in a longitudinal wave, particles of the medium vibrate in a direction that is parallel to the direction that the wave travels. places where particles of the medium crowd closer together are called compressions. places where particles of the medium spread farther apart are called rarefactions
The region of a longitudinal wave where particles are closest together is a Compression. A further explanation is below.
CompressionsThe process of re-encoding knowledge such that it consumes fewer bits of information than the original information.
Compression has been frequently sometimes used speed things up the transportation of data such as words as well as visual graphics, and even to reduce the amount of memory required to retain such content.
Find out more information about compressions here:
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what is the answer to this question?
Answer:
Vertebrae
Explanation:
Vertebrae are the 33 individual bones that interlock with each other to form the spinal column. The vertebrae are numbered and divided into regions: cervical, thoracic, lumbar, sacrum, and coccyx (Fig. 2). Only the top 24 bones are moveable; the vertebrae of the sacrum and coccyx are fused.
I believe the answer is vertebrae. There are 24 bones stacked up on each other that make up your backbone.
The number of electrons in 1.6 gram CH, is:
Answer:
6.022 x 10²³ electrons
Explanation:
can someone plz help me with this..
Answer:
Sweets are sold loose, or pre-packed in 120g bags.
The 120 g bags are £1.49 each.
The loose sweets are £0.89 for 100g.
By calculating the price per gram, determine which is better value. Show your working.
How does knowing the reactants and products
help you classify a chemical reaction? Write a
short paragraph explaining.
Answer:
Here's the Sample Response: The reactants and products determine the type of chemical reaction. If there are more products than reactants, then it is a decomposition reaction. If there are more reactants than products, it is a synthesis reaction. If oxygen is a part of the reactant, it is a combustion reaction. If one ion replaces another, it is a single replacement reaction. If there are two compounds in a reactant where cations switch, it is a double replacement reaction.
Explanation:
how many minutes does it take to drive 480 miles if you are driving 60 mph?
Answer:
480 mins
Explanation:
radiation is a measure of average kinetic energy of particles in an object true or false
Answer:false
Explanation:
Determine the molar mass of Cao
Answer:
Molar mass of CaO
(40 + 16)g
= 56g
hope it helps you
Which two statements are true about all generators?
They convert motion energy to electric energy.
They have a fixed pair of magnets and a rotating metal coil.
They’re powered by fossil fuels.
They convert electric energy to motion energy.
They use the relative motion of a magnet and a coil of wire.
Answer:
they have a fixed pair of magnets and a rolling coil they convert motion into electric energy they are powered by fosile fuels they use reletive motion of a magnet and coil of a wire
Explanation:
Answer:
They convert motion energy to electric energy.
They use the relative motion of a magnet and a coil of wire.
Explanation:
This is the correct answer.