Answer:
nutrion jsbsjsb. wjjshsjs. wjsh
Which statement accurately describes the evidence that scientists gather using fossils? Check all that apply.
Complete question is;
Which statements accurately describe the evidence that scientists gather using fossils? Check all that apply.
A) The fossil record can be used to date rocks.
B) Living things with many cells have always lived on Earth.
C) Simple organisms are found only in young rocks.
D) Geologists study ancient remains of plants and animals.
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates.
Answer:
A) The fossil record can be used to date rocks
E) Scientists can figure out what ancient living things ate.
F) Pollen and seeds help provide clues about ancient climates
Explanation:
In scientific research, fossils are sometimes referred to as animals and plant. Now, in studying records of fossils, it will be easy to know the length of existence of living things on the Earth. Also, we can be able to identify the manner in which different relationships exists between plants and animals by predicting their lifestyles, location of their habitation e.t.c which can be used to predict the old time climates.
Looking at the options given in relation to the explanation given, options A, E & F are correct
which of the following is an example of an arrthenius acid
Answer:
The common examples of Arrhenius acid includes HCl (hydrochloric acid), H2SO4 (sulphuric acid), HNO3 (nitric acid), etc.Oct 21, 2020
Explanation:
How many electrons would make the d shell complete?
Use an aufbau diagram.
1
2
6
10
Answer:
D
Explanation:
The answer for the first question is definitely D. 10, as it is a neutral atom, therefore numbers of p+ and e- are the same.
Hope it helps you
According to the electronic configuration and capacity of shells there are 10 electrons that would make the d shell complete.
What is electronic configuration?Electronic configuration is defined as the distribution of electrons which are present in an atom or molecule in atomic or molecular orbitals.It describes how each electron moves independently in an orbital.
Knowledge of electronic configuration is necessary for understanding the structure of periodic table.It helps in understanding the chemical properties of elements.
Elements undergo chemical reactions in order to achieve stability. Main group elements obey the octet rule in their electronic configuration while the transition elements follow the 18 electron rule. Noble elements have valence shell complete in ground state and hence are said to be stable.
Learn more about electronic configuration,here:
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The graph shows the volume of a gaseous product formed during two trials of a reaction. A diferent concentration of reactant was used during each trial, whereas the other factors were kept constant. Trial 2 Amount of Product Trial 1 Time Which of the following statements explains which trial has a lower concentration of the reactant? O Trial 1, because the average rate of the reaction is lower. O Trial 1, because this reaction lasted for a longer duration than Trial 2. O Trial 2, because this reaction was initially fast and later slowed down. O Trial 2, because the volume of product formed per unit time was higher
Answer:
A). Trial 1, because the average rate of the reaction is lower.
Explanation:
The first sentence elaborates that 'trial 1 had a lower level of concentration of the reactant that eventually led the reaction's average rate to fall.'
A trial having a higher level of concentration of a specific reactant will cause the concentration's average rate to rise. As per the graph provided, trial 2's average reaction rate is higher which shows that its concentration is greater and more reactive. However, the opposite happens in trial 1 where the amount of reactant is lesser in the concentration that leads the concentration to possess a lower rate of reaction. Thus, option A is the correct answer.
Over a period of 2 minutes, 180 coulombs of charge pass through a resistor. What is the current through the resistor during this time?
Type the correct answer in the box. Use numerals instead of words.
The current through the resistor during this time is
A.
Answer:
Explanation:
Formula
The current = charge / time
The charge is in coulombs
The time has to be in seconds.
1 minute = 60 seconds
2 minutes = 120 seconds.
charge = 180 coulombs
current = 180 / 120
current = 1.5 amperes.
Can someone answer this ASAP?
Carbon has unique bonding characteristics that allow it to
A
form ionic bonds with any atom to form many different molecules.
B
resist bonding with other atoms and remain a pure element.
С
form chains or rings by bonding to itself and other atoms.
D
form ionic salts that make up half of the known salts on Earth.
Answer:
С. form chains or rings by bonding to itself and other atoms.
Explanation:
Carbon is an element in group 4 of the periodic table with unique bonding properties. Carbon posseses 4 valence electrons in its outer shell. This enables carbon to form covalent bonds with the atoms of other elements e.g. nitrogen, phosphorus, oxygen, hydrogen etc.
Carbon can also combine covalently with other carbon atoms i.e. C-C to form long chains and rings in a process called CATENATION. This unique property of carbon makes it the only element that can form so many different compounds.
Which of these hypotheses cannot be tested?
A. The percentage of salt in ocean water stays the same throughout the ocean.
O B. Doubling the amount of salt in a bread recipe will cause the dough to rise faster.
C. Cooks should use sea salt in recipes instead of regular table salt.
O D. Increasing the amount of salt in salt water will increase the boiling point.
Cooks should use sea salt in recipes instead of regular table salt.
hii pls help me with this ionic equation
Answer:
net ionic equation
[tex]\boxed{ CaCO_3{}_{(s)} + 2H^{+} {}_{(aq.)} \rightarrow Ca^{2+} {}_{(aq.)} + H_2O_{(l)} + CO_2{}_{(g)} } [/tex]
Scoring Scheme: 3-3-2-1 Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used
Answer:
The solution has 0.00994 moles of Co[H2O]6Cl2
Explanation:
Complete question: Given the starting solution had a concentration of 1.25 M, how many moles of Co[H2O]6Cl2 were available in the amount of starting solution you used?
mL= 7.95
Step 1: Data given
Concentration of the starting solution = 1.25 M
Starting solution = Co[H2O]6Cl2
Step 2: Calculate molar mass of Co[H2O]6Cl2
Atomic mass of Co = 58.93 g/mol
Atomic mass of H = 1.01 g/mol
Atomic mass of O = 16.00 g/mol
atomic mass of Cl = 35.45 g/mol
Molar mass of Co[H2O]6Cl2 =
1*58.93 + 12*1.01 + 6*16.00 + 2*35.45 = 237.95 g/mol
Step 3: Calculate number of moles
C = n/v
⇒with C = the Concentration of the starting solution = 1.25 M
⇒with n= the number of moles = to be determined
⇒with v = the volume = 7.95 mL = 0.00795 L
n = C * V
n = 1.25 M * 0.00795 L
n = 0.00994 moles
The solution has 0.00994 moles of Co[H2O]6Cl2
Hiii please help me for balancing chemical equations:
potassium iodide + chlorine ------> potassium chloride + iodine
Answer:
KI + Cl2 = KCl + I2
Explanation:
hope this helps!!!
Answer:
2KI +Cl₂ → 2KCl +I₂
Explanation:
Potassium ion: K+
Iodide ion: I-
Thus, potassium iodide is KI.
Chlorine exist as a diatomic molecule thus it is written as Cl₂.
Chloride ion: Cl-
Thus, potassium chloride is KCl.
Iodine also exist as a diatomic molecule, thus it is written as I₂.
Write an unbalanced equation:
KI +Cl₂ → KCl +I₂
Now balance by ensuring the number of atoms of each element on each side is the same.
LHS
K: 1 ×2= 2
I: 1 ×2= 2
Cl₂: 2
RHS:
K: 1 ×2= 2
I: 2
Cl: 1 ×2= 2
Thus, the balanced equation is:
2KI +Cl₂ → 2KCl +I₂
What does it mean by the gas law? Can someone tell me how to do it step by step please it’s my final project
Answer:
gas laws involve the physical laws that describe the properties of gases.
Explanation:
which best describes the relationship between internal energy and thermal energy
Answer:
answer is d on edge
Explanation:
What is the percent yield of a reaction?
O A. The difference between measured and calculated amounts
OB.
The amount of produd obtained
amount possible
* 100
C. The amount of product actually obtained in a reaction
D. The amount of product that is possible from a reaction
Answer:
B. The amount of produd obtained/amount possible * 100
Explanation:
In chemistry, the yield of a chemical reaction is the quantity or amount of products obtained in that chemical reaction. It is calculated by using the following formula:
Percentage yield = Actual yield/theoretical yield × 100
- The actual yield is the amount of products got from a chemical reaction
- The theoretical yield is the amount of product got from using the balanced equation (stoichiometry).
Explain the ‘oxidation half-reaction’ and the ‘reduction half-reaction’ process.
Answer:
oxidation is the loss of electrone
reduction is gain of electrons
A sealed piston contains 400 mL of air at standard ambient pressure. The piston is
compressed to an internal volume of 125 mL while keeping a constant temperature,
What is the new internal pressure (in kPa) of the air?
Answer:
324.24 kPa
Explanation:
Given that;
Initial pressure P1 = 101325 Pa
V1= 400 ml
P2 = ?
V2= 125mL
From Boyle's law;
P1V1 = P2V2
P2 = P1V1/V2
P2= 101325 × 400/125
P2= 324.24 kPa
What is the redox half equation for 3Ag2S + 2Al --> 6Ag + Al2, and identity which material is oxidized and which is reduced? :)
Answer:
Al is oxidized while Ag is reduced.
Explanation:
The complete molecular equation is;
3Ag2S + 2Al --> 6Ag + Al2S3
Oxidation half equation;
2Al ------> 2Al^3+ + 6e
Reduction half equation;
6Ag^+ + 6e -------> 6Ag
Overall redox reaction equation;
2Al + 6Ag^+ ----->2Al^3+ + 6Ag
Hence; Al is oxidized while Ag is reduced.
6. What parts of a nuclear reactor keep the reaction from
becoming too vigorous and causing a nuclear accident?
A. Turbine and generator
B. Control rods and moderators
C. Shield and containment system
D. Condenser and cooling tower
Answer:
B. control rods and moderators
What element has the electron configuration 1522s22p63s23p4?
Answer:
Sulphur
Explanation:
1s² 2s² 2p⁶ 3s² 3p⁴
So in total ya got 16 electrons
3===> defines the period
4+12===> defines the group
and boom, there ya got yaself an element called sulphur
What makes a strong acid different from a weak acid?
Answer:
Strong acids react faster whereas weak acids take time to react with any base.
Strong acids are good conductors of electricity on contrary weak acids are not too good as conductors of electricity.
Strong acid passes electricity faster whereas weak acids are slow conductors.
Strong acids are not edible but weak acids are edible.
Strong acids have ph value ranging between 0 to 3 but the ph value of weak acids ranges between 5 to below 7.
Which of the following changes in the state of a substance results in an increase in the entropy?
Gas to solid
Gas to liquid
Liquid to solid
Solid to liquid
Answer:
the correct answer is
D. solid to liquid
If we burn 1 gr of ethyl alcohol (C2H5OH) this will translate into a release of about 50 W of thermal energy of the flame that raise the temperature of the hot and cold reservoirs of a Sterling engine at 55 °C and 95 °C respectively. If at steady state the engine turns at about 240 rpm, its gears are shaped as rings of radius ~2 cm and weigh 50 gr, how efficient (in %) is the transfer of energy via flame?
Answer:
0.116%
Explanation:
efficiency of sterling engine = 1 - ( 55 + 273 )k / ( 95 + 273 ) k
= 1 - ( 328 / 368 ) = 0.10869
Determine how efficient the transfer of energy via flame is
apply this relation ; energy of steady state / energy output ---- ( 1 )
where; energy output = efficiency of sterling engine * energy
= 0.10869 * 50 = 5.4345 J/sec
energy of steady state = 1/2 * I * w^2 ------ ( 2 )
I = moment of inertia of engine = 2 * 10^-5 kgm^2
back to equation 2 :
energy of steady state = 1/2 * ( 2 * 10^-5 ) * ( 240 * 2π / 60 )^2
= 630.88 * 10^-5 J /sec
Input values into equation 1
= [ (630.88 * 10^-5 ) / 5.4345 ] * 100
= 0.116%
All atoms of the same element:
have the same number of atoms
have the same number of protons
have the same number of neutrons
have the same number of electrons
Answer:
have the same number of protons
PLZ HELP Which of the following accurately matches a structure to its function? A. Structure: flaps of skin stretched between the front and back legs of a flying squirrel. Function: to allow the squirrel to glide on air
B. Structure: ball-and-socket joint in a human hip. Function: to allow the person to jump.
C. Structure thin membranes in webbed feet. Function: to allow the animal to walk quickly on land.
D. Structure: fish's swim bladder. Function: to allow the fish to move forward through water by releasing air from its swim bladder.
Answer:
a
Explanation:
the flying squirrel the air guides to navagate in the air
A sample of hydrogen gas H2 has a volume of 5.0 L and a pressure of 1.0 atm. What is the final pressure in atmospheres if the volume is decreased to 2 L with no change in temperature and amount of gas
Answer:
2.5 atm
Explanation:
P = Pressure
V = Volume
P1V1 = P2V2
1 x 5 = P2 x 2
5 = P2 x 2
Divide both sides by 2
5/2 = P2 x 2/2
P2 = 2.5
neutral radicals examples
Neutral radicals are always electropositive
some examples of neutral radicals are:-
Ca±±Mg±±Ba ±±Al±±NH4±Hope it is helpful to you
Calculate the solubility of Maslog at 25€
4 30-0cm of its Saturated solution at that
temperature gave 180g of the anhydrous
C= 12. 0-46. Ma =23
Salt
Answer:
20
Explanation:
calculated saturated solutions
pitch is produced by what??
Answer:
Pitch, in the chemical-process industries, the black or dark brown residue obtained by distilling coal tar, wood tar, fats, fatty acids, or fatty oils.
Explanation:
hopes it helps you☺
write molecular formula
1)aurric cloride
2)aluminium hydroxide
3)potassium thiosulphate
4)magnesium bicarbonate
5)magnesium sulphate
6)sodium oxide
7)cuprous oxide
8)mercuric oxide
9)calcium nitrate
10)aluminium oxide
11)ferric chloride
12)ammoium oxide
13)silver chloride
14)hydrogen bromide
15)magnesium nitride
16)hydrogen peroxide
17)sodium sulphate
18)ammonium sulphate
19)ferrous sulphate
20)sodium carbonate
21)zinc carbonate
22)calcium silicate
23)zinc carbonate
24)potassium clorate
25)aluminium hydroxide
26)ammonium hydroxide
27)sodium silicate
Okay.
Here's your below answers.
1) AuCl3.
2) Al(OH)3.
3) K2S2O3.
4) Mg(HCO3)2.
5) MgSO4.
6) Na2O.
7) CuO.
8) HgO.
9) Ca(NO3)2.
10) Al2O3.
11) FeCl2.
12) (NH4)2O.
13) AgCl.
14) HBr.
15) Mg3N2.
16) H2O2.
17) Na2SO4.
18) (NH4)2SO4.
19) FeSO4.
20) Na2CO3.
21) ZnCO3.
22) CaSiO3.
23) ZnCO3.
24) KClO3.
25) Al(OH)3.
26) NH4OH.
27) Na2SiO3.
Predict what would happen if a scientist added potassium to a dilute acid.
Potassium reacts with dilute hydrochloric acid to give potassium chloride and hydrogen gas. Heating small pieces of Potassium in air results in the substance melting without any flame being seen and turning instantly into a mixture of potassium peroxide and potassium super oxide.
A Potassium Reaction involves a process in which Potassium is mixed with another substance which react to form something else. Reactions are manifested by the disappearance of properties characteristic of Potassium and the appearance of new properties in the new substance or Compound.
The substances initially involved in a reaction are called reactants or reagents. The most important of the Potassium compounds is Potassium chloride (KCl) which is used in the production of fertilizers and chemicals and also as a salt substitute. Other important compounds are Potassium nitrate (KNO3), also known as saltpeter which is used in the production of gunpowder, fertilizers and pyrotechnics and Potassium hydroxide (KOH) is used to make detergents and soaps. Reactions are described with Chemical Formula and Equations.
write an equation for the reaction between nitrogen (ii) oxide and iron (ii) sulphide
Answer:
Let us write down the reaction equations for inorganic substances:
N2 + 3H2 = 2NH3 – redox reaction (ORR), ammonia was obtained;
4NH3 + 5O2 = 4NO + 6H2O – ОВР, nitrogen oxide was formed (2);
2NO + O2 = 2NO2 – ОВР, nitrogen oxide was released (4);
H2O + 2NO2 = HNO3 + HNO2 – OBP, nitric acid obtained;
2HNO3 + PbO = Pb (NO3) 2 + H2O – ion exchange, lead nitrate was formed;
2Pb (NO3) 2 = 2PbO + 4NO2 + O2 – OBP, oxygen was obtained.
The reaction products are of practical importance, for example, lead nitrate is the basis for obtaining pigments necessary for dyeing fabrics in the textile industry. These reactions show the connection of non-metals, hydrides, oxides, acids, salts.
