Answer: Abstract. The main group elements are classified as belonging to the s- and p-blocks in the periodic table. They range from gases such as fluorine and oxygen through nonmetals (e.g., boron, phosphorus, and sulfur) and semimetals (metalloids; e.g., germanium) to very reactive metals such as sodium and potassium.
Explanation:
Please tell me the answers
which one is mixture or solution
I will mark him or her as well done brilliant and thank you
Answer: Milk and chocolate/ oil and water are solution whereas fruit salad and air are mixtures
Which of the following would eat a dead rabbit?
A)
carnivore
B)
scavenger
C)
herbivore
D)
omnivore
Answer:
Scavenger
Explanation:
Because scavengers feed on dead of decaying meat
the number of moles of hydrogen that are needed to produce .253 moles of water
Answer:
454
Explanation:
j
A stable atom that has a large nucleus most likely contains?
O more neutrons than protons.
more protons than neutrons.
O equal numbers of protons and neutrons.
C changing numbers of protons and neutrons.
Answer:
equal numbers of protons and neutrons
Chromatography and fractional distillation can be used to separate compounds.
In which type of separation is a thermometer needed for checking that complete separation has
occurred?
A chromatographic separation of two colourless solids
B chromatographic separation of two solids of different colours
C fractional distillation of two colourless liquids
D fractional distillation of two liquids of different colours
Answer:
fractionao distillation of two colourless liquids
NEED HELP ASAP!
When heated, cyclopropane is converted to propene. Rate constants for this reaction at 470. °C and 510. °C are k1 = 1.10 × 10-4 s-1 and k2 = 1.02 × 10-3 s-1, respectively. Determine the activation energy, Ea, from these data.
Answer:
1.06 × 10^5 J
Explanation:
We have to use the formula;
log(k2/k1) = Ea/2.303 ×R (1/T1 - 1/T2)
Given that;
k1 = 1.10 × 10-4 s-1
k2= 1.02 × 10-3 s-1
Ea=?
R=8.314 Jmol-1K-1
T1= 470. °C
T2= 510. °C
Hence;
log(1.02 × 10-3 s-1/1.10 × 10-4 =Ea/2.303 ×8.314(1/470 -1/510)
0.9672 = Ea/19.122(2.13 - 1.96) × 10^-3
0.9672= Ea/19.122(0.17) × 10^-3
0.9672= 1.7 ×10^-4 Ea/19.122
19.122 × 0.9672 = 1.74 × 10^-4Ea
Ea= 19.122 × 0.9672/1.74 × 10^-4
Ea= 18.495/1.74 × 10^-4
Ea= 1.06 × 10^5 J
A pupil adds 5 cm of 12 mol.dm sulphuric acids to make a 250 cmº solution. Calculate the
concentration of the diluted acid.
Answer:
0.500 mol/dm³
Explanation:
Using the formula below;
CaVa = CbVb
Where;
Ca = concentration of acid (mol/dm³)
Cb = concentration of base (mol/dm³)
Va = volume of acid (cm³)
Vb = volume of base (cm³)
In accordance to the information provided in this question is;
Va = 5cm³
Vb = 250 cm³
Ca = 12 mol/dm³
Cb = ?
Using CaVa = CbVb
12 × 5 = Cb × 250
60 = 120Cb
Cb = 60/120
Cb = 0.500 mol/dm³
naming organic compounds: multiple choice
Answer:
3) C: Structure should have 6 carbon with double beginning on the 2nd carbon atom.
4) D: structure should have 5 carbon with triple bond beginning on the first carbon atom.
5) A: 4
Explanation:
3) The molecular formula for hexene is C6H12. This means it has 6 carbon atoms. However, the suffix "ene", means that it contains an alkene and thus it has 2 double bonds connecting 2 carbon atoms.
Looking at the options, the correct one is Option C.
4) The molecular formula for 1-pentyne is given by; C5H8.
This means there are 5 carbon atoms. However, the suffix "yne" means there is a presence of ethyne and thus it has triple bond.
Looking at the options, the only correct one is Option D
5) Since the number of carbon atoms are 3 and it has triple bond, then it means this is likely propyne
Now, the formula is C3H4 which is;
chemical formula CH3C≡CH
Thus, the number of hydrogen atoms with at least 1 carbon-carbon triple bond is 4.
Describe the traits of a reliable investigation.
Answer:
Every science experiment should follow the basic principles of proper investigation so that the results presented at the end are seen as credible.
Observation and Hypothesis. ...
Prediction and Modeling. ...
Testing and Error Estimation. ...
Result Gathering and Presentation. ...
Conclusions. ...
Law Formation.
Using the balanced equation below,
how many grams of manganese(III)
oxide would be produced from the
complete reaction of 46.8 g of zinc?
Zn + 2MnO2 + H20 — Zn(OH)2 + Mn203
Answer: The mass of manganese(III) oxide produced is 113.03 g
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ......(1)
Given mass of zinc = 46.8 g
Molar mass of zinc = 65.38 g/mol
Plugging values in equation 1:
[tex]\text{Moles of zinc}=\frac{46.8g}{65.38g/mol}=0.716 mol[/tex]
The given chemical equation follows:
[tex]Zn+2MnO_2+H_2O\rightarrow Zn(OH)_2+Mn_2O_3[/tex]
By the stoichiometry of the reaction:
If 1 mole of zinc produces 1 mole of manganese(III) oxide
So, 0.716 moles of zinc will produce = [tex]\frac{1}{1}\times 0.716=0.716mol[/tex] of manganese(III) oxide
Molar mass of manganese(III) oxide = 157.87 g/mol
Plugging values in equation 1:
[tex]\text{Mass of manganese(III) oxide}=(0.716mol\times 157.87g/mol)=113.03g[/tex]
Hence, the mass of manganese(III) oxide produced is 113.03 g
In the diagram below, what will allow more solute to be dissolved in the
solvent?
Answer:
missin a diagram buddy
Explanation:
A d orbital can
hold ____ electrons.
A. 2
B. 6
C. 10
D. 14
Answer:
10 electrons
Explanation:
Does anyone have Chem2 Test please, I really need it!
Answer:
whick level are u on
I am not faking an answer but I cann arrange it to u if possible
Why do we not see a solar and lunar eclipse every lunar cycle?
Answer:
Explanation: We don't see lunar eclipses every cycle because the Moon's orbit is tilted five degrees from Earth's orbit around the Sun. And when an eclipse occurs the earth passes directly between Sun and Moon.
A chemical reaction done at STP conditions is supposed to produce 0.011 moles of CO2 gas. How many liters of gas will that be?
Answer:
V = 0.24 L.
Explanation:
Hello there!
In this case, it is possible to approach this problem by using the ideal gas equation defined by:
[tex]PV=nRT[/tex]
Whereas our unknown is V, volume, and we solve for it as follows:
[tex]V=\frac{nRT}{P}[/tex]
Then since the STP conditions are ate 273.15 K and 1 atm, the volume of 0.011 moles of CO2 gas turns out to be:
[tex]V=\frac{0.011mol*0.08206\frac{atm*L}{mol*K}*273.15K}{1atm}\\\\V=0.24L[/tex]
Regards!
Some forms of vitamin D, C₂₈H₄₄O, can be found in red meat. How many total atoms are in 5 molecules of C₂₈H₄₄O
Answer:
3.01 × 10^24 atoms of vitamin D
Explanation:
The number of atoms, molecules or ions present in a substance is given by the Avogadro's number which is 6.02 × 10^23.
Hence;
1 molecule of vitamin D contains 6.02 ×10^23 atoms
5 molecules of vitamin D contains 5 × 6.02 ×10^23/1
= 3.01 × 10^24 atoms of vitamin D
What will happen if the cloud does not have enough mass?
A core will form.
A star will not form.
A protostar will form.
A nebula will not form.
the swallowtail caterpillar is an example of a ?
Answer:
B) Consumer COnsumer COnsumer
Answer:
Consumer
Explanation:
It is a consumer
Sodium reacts with chlorine to form sodium chloride. Which statements describe what happens to the sodium atoms in this reaction? 1. Sodium atoms form positive ions. 2. Sodium atoms form negative ions. 3. Sodium atoms gain electrons. 4. Sodium atoms lose electrons a. 1 and 3 b. 1 and 4 c. 2 and 3 d. 2 and 4
Answer: The correct option is b) 1 and 4.
Explanation:
An ionic compound is formed when a complete transfer of electrons takes place from one element (usually metals) to another element (usually non-metals).
The element (metal) that loses electrons forms a positive ion which is known as cation while the element (non-metal) that gains electrons forms a negative ion which is known as an anion.
Sodium chloride is an ionic compound that is formed by the combination of sodium and chloride ions.
Sodium is the 11th element of periodic table having electronic configuration of [tex]1s^22s^22p^63s^1[/tex]
It will lose 1 electron to form a positive in having a chemical formula of [tex]Na^+[/tex]
Therefore, the statements that say, sodium atoms form positive ions and sodium atoms will lose electrons are correct.
Thus, the correct option is b) 1 and 4.
What mass of water can be heated from 45°C to 70°C by the addition of 875 Joules?
Please I need this
Answer:
17000 joules.
Explanation:
Explanation:
With knowledge of the specific heat capacity of a substance, its mass, and the temperature change, we can convert this to the energy required for this temperature change using:
ΔH=mCΔT, where
ΔH=change in enthalpy (J)
m= mass of substance being heated (g) i.e. water in this question
C= specific heat capacity (J/g°C)
ΔT= change in temperature (°C)
We know mass=65g and ΔT=76°C−12°C=64°C
The specific heat capacity of water is 4.18J/g°C
Therefore, ΔH=65g⋅4.18Jg°C⋅64°C
=17388.8J
=17000J (2 significant figures)
Name the functional group in the following molecule:
Answer:
carboxyl group you said "functional group" not homologous series!
Answer:
Option "B":"Carboxyl group"
Explanation:
What is altered by a catalyst?
a) average kinetic energy of products
b) activation energy
c) difference between the energies of products and reactants
d) average kinetic energy of reactants
Answer:Effect of Catalysts on the Activation Energy. Catalysts provide a new reaction pathway in which a lower Activation energy is offered. A catalyst increases the rate of a reaction by lowering the activation energy so that more reactant molecules collide with enough energy to surmount the smaller energy barrier.
Explanation:
Your answer is in this
In a chemical equation which shows presence of catalyst, activation energy is altered.
What is chemical equation?Chemical equation is a symbolic representation of a chemical reaction which is written in the form of symbols and chemical formulas.The reactants are present on the left hand side while the products are present on the right hand side.
A plus sign is present between reactants and products if they are more than one in any case and an arrow is present pointing towards the product side which indicates the direction of the reaction .There are coefficients present next to the chemical symbols and formulas .
The first chemical equation was put forth by Jean Beguin in 1615.By making use of chemical equations the direction of reaction ,state of reactants and products can be stated. In the chemical equations even the temperature to be maintained and catalyst can be mentioned.
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Which area of science is considered the central science?
O chemistry
O biology
O physics
O environmental science
Answer:
Chemistry
Explanation:
Chemistry helps connect the types of physcial sciences.
Which of the following would have the best thermal insulation properties?
A. A cotton sweater
B. A rubber rain_at
C. A down-filled coat
D. A nylon windbreaker
Answer:
C. A down-filled coat via a p e x
Thermal insulation maintains the temperature inside the system and inhibits heat transfer. A down-filled coat would have the best thermal insulation properties. Thus, option C is correct.
What is thermal insulation?Thermal insulation is the property of the substance to resist the heat and energy transfer from a substance of abundance to a lesser concentration. They lack the conducting particles.
It inhibits the heat to get transferred to other substances. The minimum heat transfer is achieved by the structural formation and the choice of the substance.
A down-filled coat is made of insulation material that keeps warm during the winters as its structure can trap and retain heat making the person warm during colds.
Therefore, option C. A down-filled coat best shows thermal insulation.
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!
Hormones keep our bodies in a state of
balance known as
(a)metabolism
(b)homeostasis
The force of gravity pulling down on the
barbell is 756 newtons (N) How many
newtons of force are exerted by the
weightlifter to hold the barbell up?
Answer:
Explanation:
The same. The force down (the weight of the barbells) is counter balanced by the weight up ( a person holding the barbells). A little later on, you are going to draw force diagrams showing that these two forces are drawn acting in opposite directions.
You can satisfy yourself by drawing a box and putting 1 arrow pointing up on the bottom and labeling it 756 up and another arrow on the top of the box pointing down and labeling it 756. They balance.
ionic compounds have __ boiling points and molecular compounds have __ boiling points
a: high,low
b: low,low
c: low,high
d: high,high
Answer:
A
Explanation:
because ionic bond have stronger electrostatic force of attraction between oppositely charged particles so it has higher boiling point than molecular which is covalent bond and have low boiling point hope this helps to understand ^_^
If 50 milliliters of a 1.0M NaOH solution is
needed to exactly neutralize 10 milliliters of an
HCI solution, the molarity of the HCl solution is
A. 1.0M
B. 0.20 M
C. 5.0M
D. 10M
Answer:
c
Explanation:
The molarity of the HCl solution is 5M and the correct option is option C.
What is Molarity?Molarity is a unit of concentration measuring the number of moles of a solute per litre of solution.
Chemists primarily need the concentration of solutions to be expressed in a way that accounts for the number of particles that react according to a particular chemical equation. Since percentage measurements are based on either mass or volume, they are generally not useful for chemical reactions. A concentration unit based on moles is preferable.
Given,
Volume of NaOH = 50 ml
Concentration of NaOH = 1M
Volume of HCl = 10ml
Concentration of NaOH × Volume of NaOH = Concentration of HCl × Volume of HCl
1 × 50 = c × 10
Concentration of HCl = 5 M.
Therefore, the molarity of the HCl solution is 5M and the correct option is option C.
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Energy cycles through ecosystems because it returns to the Sun.
True
or
False
Answer:
FALSE
Explanation:
Energy does not cycle the way nutrients and atoms do. Energy enters the ecosystem from the Sun and exits after the organisms have taken as much as they need. Organisms release energy back into the biosphere as heat. ... It is usually in the form of heat, not the electromagnetic radiation from the Sun.
Write a balanced nuclear equation for the alpha decay of titanium-45.
Explanation:
20984Po→20582Pb+42α
4520Ca→4521Sc+0-1e+00ν
Explanation:
The alpha decay of polonum-209, which consists of the emission of an alpha particle, will leave behind the atom of a different element.
Notice that the identity of the element changes after the decay. This means that you're dealing with a nuclear transmutation, a process that converts an atom of a given element into an atom of a different element.