Answer:
I think the answer is B :)
Answer:
the first step is B
Explanation: I'm on this lesson
what is heavier 1 pound of bricks or 1 pound of feathers
Answer:
They are both the same.
Explanation:
ONE POUND of feathers
ONE POUND of brick
Answer:
They are both the same
Explanation:
Even though feathers are lighter they are both 1 pound. Why do you have so many feathers?!?!?
How many protons does Hydrogen contain?
Answer:
1
Explanation:
The reaction below shows how the potential energy changes during a
chemical reaction. What does the red arrow show?
Answer:
Option C. Change in enthalphy is negative, the reaction is exothermic.
Explanation:
In the profile diagram given in the question above, we can see clearly that the energy of the reactant (Hr) is higher than the energy of product (Hp).
Hence, the enthalpy change (ΔH) will be negative i.e
Enthalpy change (ΔH) = Energy of product (Hp) – Energy of reactant (Hr)
ΔH = Hp – Hr = negative (–) [since Hr is higher than Hp]
A reaction in which the enthalpy change (ΔH) is negative is termed exothermic reaction.
Which of the following contribute(s) to most of the mass of an atom?
Question 6 options:
A)
Neutrons only
B)
Protons and neutrons
C)
Protons and electrons
D)
Protons only
Question 7 (5 points)
In a certain chemical reaction, the bonds of the products contain more energy than the bonds of the reactants. For the reaction to occur, which of the following best describes what occurred?
Question 7 options:
A)
Energy was released, so the reaction is endothermic.
B)
Energy was released, so the reaction is exothermic.
C)
Energy was added, so the reaction is endothermic.
D)
Energy was added, so the reaction is exothermic
Question 8 (5 points)
A solution
Question 8 options:
A)
is a single-phase homogeneous mixture.
B)
must contain water.
C)
is always a liquid.
D)
can contain more than two phases.
Question 9 (5 points)
Which of the following is true of alloys?
Question 9 options:
A)
They can only be composed of metals.
B)
They must be held together by chemical bonds.
C)
They're liquid solutions.
D)
They must contain a metal.
Question 10 (5 points)
Which of the following best describes an atomic number? An element's identity is defined by its atomic number; this means it represents the number of
Question 10 options:
A)
electrons in the element.
B)
neutrons in its nucleus.
C)
protons plus neutrons in its nucleus.
D)
protons in its nucleus.
Answer:
1.
B) protons and newtrons
2.
D)
3.
C)
4.
A)
What is another name for radioactive dating?
Answer:
radioisotope dating is another name
Answer:
Radiometric dating
Explanation:
hope that helps
In chemistry lab, a student measured the density of liquid ethanol is 0.789 g/mL. Represent its density in units of 1b /in3? (2.54 cm = 1 in., 2.205 lb = 1 kg)
A. 9.09 x 10+ 1b / in
B.4.42 x 10-1b / in?
OC.2.85 x 10-2 16 / in
D. 0.106 16 / in?
O E.5.86 x 10" 16/in3
Answer:
Option C is correct option = 2.85×10⁻² lb/in³
Explanation:
Given data:
Density in g/mL = 0.789
Density in lb/in³ = ?
Solution:
It is given that,
2.54 cm = 1 in
2.205 lb = 1 kg thus,
1 mL = 1 cm³
0.789 g/cm³ × 1 kg/ 1000 g × 2.205 lb/1 kg × (2.54 cm / 1in)³
2.85×10⁻² lb/in³
The density of liquid ethanol is 0.789 g/mL, which is equivalent to 0.0285 lb/in³.
A student measured the density of liquid ethanol to be 0.789 g/mL and we want to convert it to lb/in³. We will need a series of conversion factors.
What is a conversion factor?A conversion factor is an arithmetical multiplier for converting a quantity expressed in one set of units into an equivalent expressed in another.
Step 1: Convert 0.789 g/mL to lb/mLWe will use the following conversion factors:
1 kg = 1000 g.1 kg = 2.205 lb.0.789 g/mL × (1 kg/1000 g) × (2.205 lb/1 kg) = 1.74 × 10⁻³ lb/mL
Step 2: Convert 1.74 × 10⁻³ lb/mL to lb/in³We will use the following conversion factors:
1 mL = 1 cm³.1 in = 2.54 cm.1.74 × 10⁻³ lb/mL × (1 mL/1 cm³) × (2.54 cm/1 in)³ = 0.0285 lb/in³
The density of liquid ethanol is 0.789 g/mL, which is equivalent to 0.0285 lb/in³.
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WHAT IS A NEWTON!! specifically the definition!!!!
Answer:
Explanation:
the SI unit of force. It is equal to the force that would give a mass of one kilogram an acceleration of one meter per second per second, and is equivalent to 100,000 dynes.
When an atom is trying to obtain stability, what part(s) of the atom change(s)?
When an objects volume is made smaller and it’s mass remains the same it’s density
What change would you expect on the rate of the SN2 reaction of 1-iodo-2-methylbutane with cyanide ion if the nucleophile concentration is halved and the alkyl halide concentration is doubled
Answer:
The rate of reaction remains the same, no change is observed
Explanation:
Remember that for an SN2 reaction, the rate of reaction depends both on the concentration of the alkyl halide and the concentration of the nucleophile.
Hence we can write; Rate = k [Alkyl halide][NaI]
This implies that if we half the concentration of the nucleophile and double the concentration of the alkyl halide, the rate of reaction just remains the same since the reaction is bimolecular and first order in both alkyl halide and nucleophile
Which properties do not change the composition of a substance?
neither chemical nor physical properties
physical properties
chemical properties
chemical and physical properties
Answer:
Physical Properties
Explanation:
PHYSICAL PROPERTY
Answer:
phycical propertys
Explanation:
jut took the test got it right
Help asap!!!!
What are elements in the tall columns of the periodic table called?
A. Representative elements
B. Valence elements
C. Atomic elements
D. Period elements
The elements in the tall columns of the periodic table are called representative elements or main group elements. They exhibit similar chemical properties within their respective groups due to their shared number of valence electrons. The terms "valence elements," "atomic elements," and "period elements" are not commonly used or recognized in the context of the periodic table.
The correct answer is option A.
The elements in the tall columns of the periodic table are called "A. Representative elements," also known as the "main group elements" or "group A elements." These elements are found in groups 1, 2, and 13 to 18 (excluding the transition metals) on the periodic table.
Representative elements are characterized by having similar chemical properties within their respective groups. This similarity arises from the fact that elements within the same group have the same number of valence electrons, which are the electrons in the outermost energy level of an atom. Valence electrons play a crucial role in determining the chemical behavior and reactivity of an element.
The representative elements include the alkali metals (Group 1), alkaline earth metals (Group 2), boron group (Group 13), carbon group (Group 14), nitrogen group (Group 15), oxygen group (Group 16), halogens (Group 17), and noble gases (Group 18). These elements exhibit a wide range of properties, from highly reactive metals to nonmetals and inert gases.
The term "valence elements" mentioned in option B is not commonly used in the context of the periodic table. Valence electrons are indeed significant in determining chemical properties, but they are not specific to the elements in the tall columns. Valence electrons are found in elements across the periodic table.
"Atomic elements" mentioned in option C is a vague term and does not specifically refer to the elements in the tall columns. All elements on the periodic table are atomic in nature, as they are composed of atoms.
"Period elements" mentioned in option D is not a recognized term in the context of the periodic table.
In conclusion, the elements in the tall columns of the periodic table are known as representative elements or main group elements. These elements exhibit similar chemical properties within their respective groups due to their shared number of valence electrons.
Therefore, from the options provided the correct one is A.
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A sample contains 110.68 g of calcium. How many moles is this?
(1 mole Ca = 40.08 g)
Round to the nearest tenth and do NOT include a unit. (.e. 2.9)
Helppppp
Answer:
About 2.8
Explanation:
Imagine there is technology that allows scientists to see all of the movement of molecules inside living things. A scientist points this machine at the stem of a vascular plant and sees glucose molecules being transported to various parts of the plant. The scientist is looking at the movement of molecules through
the xylem.
the phloem.
the roots.
the cuticle.
Answer: C
Explanation: I looked it up lol
2. Using the following data, calculate the average atomic mass of magnesium (give your answer to the nearest
.01 ) : Show all work!
Isotope: Mg Percent abundance: 78.70%
24
Isotope: 'Mg Percent abundance: 10.13%
25
Isotope:
Mg Percent abundance: 11.17%
26
Answer:
24.32
Explanation:
From the question given above, the following data were obtained:
Isotope A:
Mass of A = 24
Abundance (A%) = 78.70%
Isotope B
Mass of B = 25
Abundance (B%) = 10.13%
Isotope C:
Mass of C = 26
Abundance (C%) = 11.17%
Average atomic mass of Mg =..?
The average atomic mass of Mg can be obtained as illustrated below:
Average atomic mass = [(Mass of A × A%)/100] + [(Mass of B × B%)/100] + [(Mass of C × C%)/100]
Average atomic mass = [(24 × 78.70)/100] + [(25 × 10.13)/100] + [(26 × 11.17)/100]
= 18.888 + 2.5325 + 2.9042
= 24.3247 ≈ 24.32
Therefore, the average atomic mass of magnesium (Mg) is 24.32
What was the average speed of the truck for this trip?
Answer:
31.67 mph
Explanation:
To calculate the average speed of the truck, we must first obtain the total distance travelled by the truck followed by the total time taken for the truck to cover the distance travelled.
The following data were obtained from the question include:
Total distance) = 30 + 45 + 50 + 65 = 190 miles
Total time = 1 + 2 +1 +2 = 6 hours
Average speed =.?
Average speed = Total distance / Total time
Average speed = 190 /6
Average speed = 31.67 mph
Therefore, the average speed of the truck is 31.67 mph
The force of 20 N acts upon a 5kg block. What is the acceleration of the block?
100 m/s/s
4 m/s/s
O 25 m/s/s
O 0.25 m/s/s
Answer:
The answer is 4 m/s²Explanation:
The acceleration of an object given it's mass and the force acting on it can be found by using the formula
[tex]a = \frac{f}{m} \\ [/tex]
where
a is the acceleration
f is the force
m is the mass
From the question
f = 20 N
m = 5 kg
We have
[tex]a = \frac{20}{5} \\ [/tex]
We have the final answer as
4 m/s²Hope this helps you
A student conducting a calorimetry investigation determines a negative ∆H. What does the negative value indicate about the reaction?
A. The reaction synthesized a single product.
B. The reaction was exothermic.
C. The reaction absorbed energy.
D. The reaction involved decomposition.
Answer:
a
Explanation:
correct
Briefly explain why the bulk temperature of the water remains low (at room temperature)
How would a descriptive model of Earth's layers be categorized?
a. abstract model
b. prototype model
c. concrete model
d. conceptual model
A descriptive model of Earth's layers can be categorized as prototype model. Hence, option B is correct.
What is a descriptive model?
A descriptive model describes a system or other entity and its relationship to its environment.
The Earth has different compositional and mechanical layers. Compositional layers are determined by their components, while mechanical layers are determined by their physical properties.
The outermost solid layer of a rocky planet or natural satellite. Chemically distinct from the underlying mantle.
Hence, option B is correct.
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Which of the following is a process that changes the composition of rocks from one material to another? (3 points) a Erosion b Deposition c Physical weathering d Chemical weathering
Answer:
ERosion i think
Explanation:
Answer:
Deposition
Explanation:
I hope you have a nice day(:
How much heat, in kilojoules, must be added to a 580 g aluminum pan to raise its temperature from 25∘C to 150∘C?
---The specific heat capacity for aluminum is 0.897 J/g∘C.
---Round the answer to two significant figures.
Answer:
Q = 65 kJ
Explanation:
Given that,
Mass, m = 580 g
Initial temperature, [tex]T_i=25^{\circ} C[/tex]
Final temperature, [tex]T_f=150^{\circ} C[/tex]
The specific heat capacity for aluminum is 0.897 J/g°C
We need to find the heat added to the aluminium pan so that its heat raised to a temperature from 25°C to 150°C. It is given by :
[tex]Q=mc\Delta T\\\\Q=580\ g\times 0.897\ J/g^{\circ} C\times (150-25)^{\circ} C\\\\Q=65032.5\ J[/tex]
or
Q = 65.03 kJ
or
Q = 65 kJ
Hence, the heat added to the pan is 65 kJ.
How is the periodic table generally arranged?
Answer:
It is generally arranged by the atomic number
Explanation:
If you added an excess of sodium phosphate dodecahydrate to 4.512 g barium chloride dihydrate, how many grams of barium phosphate could you synthesize
Answer:
3.35g of Ba3(PO4)2
Explanation:
The balanced chemical equation is given as;
3 BaCl2 + 2 Na3PO4 → 6 NaCl + Ba3(PO4)2
Fro the reaction;
3 mol of BaCl2 (624g) reacts wth 2 mol of Na3PO4 (327.88g) to form 1 mol of Ba3(PO4)2 (601.93g)
Since Na3PO4 is in excess, the limiting reactant is; BaCl2. It would determine how much of Ba3(PO4)2 is formed.
624g of BaCl2 = 601.93g of Ba3(PO4)2
4.512g of BaCl2= xg of Ba3(PO4)2
x = 4.512g * 601.93g / 624g
x = 3.35g of Ba3(PO4)2
The mass of barium phosphate synthesized is 3.612 g.
The equation of the reaction is;
3 BaCl2.2H2O + 2 Na3PO4.12 H2O → 6 NaCl + Ba3(PO4)2 + 14H2O
Molar mass of barium chloride dihydrate = 244.26 g/mol
The number of moles of barium chloride dihydrate = 4.512 g/244.26 g/mol
= 0.018 moles
From the balanced reaction equation shown;
If 3 moles of barium chloride dihydrate yields 1 mole of barium phosphate
0.018 moles of barium chloride dihydrate yields 0.018 moles × 1 mole/3 moles
= 0.006 mole of barium phosphate
Mass of barium phosphate = 602 g/mol × 0.006 mole
= 3.612 g
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Convert 2.6 x 106 mL to L.
Answer:
0.2756 L
Explanation:
0.2756 L
The strength of an acid is affected by the polarity of the bond connected to the acidic hydrogen. The more highly polarized this bond, the more easily the hydrogen is ionized. Electronegative atoms or groups of atoms present in the structure of an acid can act to withdraw electrons and produce additional polarization. Two common groups of acids to which this principle can be applied are oxyacids and carboxylic acids. Arrange the following oxyacids in order of decreasing acid strength. Rank from strongest to weakest acid.
a. HBrO
b. HClO
c. HClO3
d. HClO2
Answer:
Explanation:
Oxyacids are acid containing oxygen; they are also known as acid-alcohol or acid-phenol. As said earlier, the strength of these acids increases with increases in the polarity of these compounds. So, what makes the polarity is as a result of the electronegative substituents attached to it. Halogen family possesses the highest electronegativity in the periodic table, and electronegativity decreases down the group.
The ranking of the oxyacids in order of decreasing acid strength from strongest to weakest acid is:
HClO3 > . HClO2 > HClO > HBrO
Subscripts are used in a chemical formula to show the number of atoms of each element.
True or False.
If endothermic means that the temperature increases and exothermic means it decreases, it 64 degrees to 64 degrees (it stayed the same) endothermic or exothermic?
Answer:
The answer is none of them.
Explanation:
I did the study guide...Also, if it has no change, it is neither.
Which among the given combinations below represent a set of isotopes?
1.40 protons and 40 neutrons
II. 41 protons and 39 neutrons
3.42 neutrons and 48 protons
4 40 protons and 42 neutrons
V. 41 protons and 40 neutrons
A. I, II, III
B. III, IV
C.1, IV and II, V
D. 1, V and II. V
E.1. V
Look for the ones with the same number of protons and different neutrons number
why is water a neutral substance
Answer: Water is considered neutral because the concentration of hydrogen and hydroxide ions is the same
Explanation:
An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of helium, carbon dioxide, and nitrogen. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest. An aqueous solution is in equilibrium with a gaseous mixture containing an equal number of moles of helium, carbon dioxide, and nitrogen. Rank the relative concentrations of each gas in the aqueous solution from highest to lowest.
[CO2][CO2] > [He][He] > [N2][N2] [N2][N2] > [CO2][CO2] > [He][He] [CO2][CO2] > [N2][N2] > [He][He] [He][He] > [N2][N2] > [CO2][CO2]
Answer:
[CO2] > [N2] > [He]
Explanation:
The relative concentration of CO2, N2 and He depends on the solubility of each gas in water. The more soluble in water a gas is, the greater its concentration in aqueous solution.
Among the gases listed, CO2 is most soluble in water hence it is expected to have the greatest concentration in solution followed by N2. Helium gas is insoluble in water hence it has the least concentration in the aqueous solution.