Which of these is a characteristic of science? (5 points) Question 1 options: 1) It cannot be reproduced by any scientist. 2) It cannot be changed by new knowledge. 3) It is based on empirical evidence. 4) It is guided by a set of values.
Answer:
3
Explanation:
It is based on empirical evidence
The characteristic of science is that it is based on empirical evidences comprising of a hypothesis.
What is a hypothesis?
Hypothesis can be defined as an assumption which is made for the sake of argument . It is an interpretation of a practical condition for which action needs to be taken.It is defined as a tentative assumption which is made to test logical consequences.It is an antecedent clause of a statement which is conditional.
It is constructed before research. There are six types of hypothesis 1)simple hypothesis 2) complex hypothesis 3) directional hypothesis 4)non-directional hypothesis 5) null hypothesis 6)casual hypothesis
The hypothesis should be clear and precise, it must be specific and way of explanation of hypothesis should be simple.
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help me please!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
In the compound Al2O3, aluminum has an oxidation number of 3, while oxygen's oxidation number is ________.
Answer:
The oxidation number of Oxygen is -2.
Answer:
-2
Explanation:
I just had that question!
Covalent bonds involve the sharing of?
Answer:
A covalent bond is a chemical bond that involves the sharing of electron pairs between atoms. These electron pairs are known as shared pairs or bonding pairs, and the stable balance of attractive and repulsive forces between atoms, when they share electrons, is known as covalent bonding.
Explanation:
I hope this helps
Particles of a liquid
A. Are free to move in a container but remain in close contact with one another
B. Are tightly packed together and stay in a fixed position
C. Have no viscosity
D. Decrease in volume with increasing temperature
Answer:
A
Explanation:
B. That's a solid
C. Liquid is the only thing that can have viscosity
D. Not necessarily the case
butter is made by intentionally changing the density of the milk. Try to find out how this change is made and describe it briefly. Explain these changes using particle theory
PLS HELP I RLY NEED IT :)
Answer:
As temperature increases, a substance will change from solid, to liquid, to gas. ... Apply Butter is made by intentionally changing the density of liquid milk.
Explanation:
How can the conductivity of a salt solution be decreased?
A. Add more salt to increase the concentration.
B. Add more water to decrease the concentration.
C. Add more water to increase the concentration.
D. Add more salt to decrease the concentration.
Answer:
B. Add more water to decrease the concentration.
Explanation:
If we add more water to the solution, the concentration is decreased and like wise the conductivity of the solution.
Concentration is the amount of solute in a solution. Conductivity deals with the ability of a solution to allow the passage of current.Concentration and conductivity are directly proportional to one another. The higher the concentration, the higher the conductivity and vice versa.
Adding more water increases the amount of solvent and the concentration reduces.A 1.0 kg ball is thrown into the air and initial velocity of 30 mi./s how high into the air did the ball travel
Answer:
45.9m
Explanation:
Given parameters:
Mass of the ball = 1kg
Initial velocity = 30m/s
Unknown:
Height the ball will travel = ?
Solution:
At the maximum height, the final velocity of the ball will be 0;
Using ;
V² = U² - 2gh
V is the final velocity
U is the initial velocity
g is the acceleration due to gravity
h is the height
0² = 30² - (2 x 9.8 x h)
0 = 900 - 19.6h
h = 45.9m
What is the number of protons for 2^1H?
How many atoms are there in 2.0 moles of magnesium (Mg)?
A. 1.2 x 1024
B. 2.0 x 1022
C. 6.0 x 1021
D. 3.0 x 1023
Answer:
It should be 1. 1.2 X 10^24
Explanation:
Which element below would most likely gain 3 electrons?
Answer:
Lithium
Explanation:
A 15.33 g sample of magnesium oxide is found to contain 12.67 g of magnesium. What is the percent (by mass) composition of
the magnesium in the compound?
026 Ma
Answer:
Explanation:
I can help
Answer:
12.67g of Mg / 15.33g of MgO * 100% = 82.6% of Mg
Explanation:
What is the atomic number of silicon
Answer:
The atomic number of silicon 14
According to periodic table
The atomic number of silicon is 14
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What type of energy is described as electrons moving in a circuit?
Answer:
Electrical energy (form of kinetic energy)
Explanation:
Observe the image of sodium. List the properties you see.
Answer:
It is soft and white. It has a low melting and boiling point, a good conductor electricity, and reacts with water. Furthermore, it is also highly reactive, malleable, and ductile.
Explanation:
Hope I helped!
Answer:
silvery-white and waxy
Explanation:
Properties means the observations you can make just by looking at it or the qualities that the object has.
So when I looked at the sodium I saw a silvery-white metal (sodium is a metal), that has this waxy appearance to it.
The total mass of an atom expressed in atomic mass units is known as the *
mass number.
atomic number.
isotopic number.
covalent number.
Answer:
c
Explanation:
2. How many atoms are in 5.6 moles of Na? Answer:___3.2 E 24 atoms of Na
Answer:
5.6[tex]\frac{6.02*10^{23} }{1}[/tex] = 3.4 X [tex]10^{24}[/tex]
Explanation:
the correct answer to it is 3.4 instead of 3.2. I got 3.4 from rounding it from 3.37.
The number of atoms in 5.6 moles of Na have been [tex]\rm \bold{3.37\;\times\;10^2^4}[/tex] atoms.
Atoms have been defined as the smallest unit of matter. The number of atoms in a mole of compound has been given by Avogadro law.
According to the Avogadro law, the number of atoms in mole of sample has been equal to the Avogadro number. The values of Avogadro number has been [tex]6.023\;\times\;10^2^3[/tex].
Computation for the atoms in NaThe available moles of Na have been 5.6 moles.
The number of atoms has been given by:
[tex]\rm 1\;mol=6.023\;\times\;10^2^3\;atoms\\ 5.6\;mol=5.6\;\times\;6.023\;\times\;10^2^3\;atoms\\ 5.6\;mol=3.37\;\times\;10^2^4\;atoms[/tex]
The number of atoms in 5.6 moles of Na have been [tex]\rm \bold{3.37\;\times\;10^2^4}[/tex] atoms.
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Give the symbol for the element with the following orbital diagram:
↑↓
1s
0000
↑↓
2s
0000
↑↓
↑↓
2p
↑↓
0000
↑↓
3s
0000
↑↓
↑↓
3p
↑↓
0000
↑↓
4s
0000
↑↓
↑↓
↑↓
3d
↑↓
↑
The given orbital diagram are iron and symbol for the element is Fe
Orbital diagrams are a pictorial description of electrons in an atom and where electron go in atom then we have to follow three rules, and the first one being the Auf bau Principle, the Auf bau Principle states that each electron occupies the lowest energy orbital first filled and the second is pauli exclusion principle in which only two electron are present which is in opposite spin and third is hunds rule of maximum multiplicity in which pairing of electron is not possible until orbital are singly occupied this rules are used for filling the electron here given orbital diagram in which 1s²2s²2p⁶3s²3p⁶4s²3d⁶ means the element is iron and symbol of this element is Fe
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Displacement reaction between copper and silver nitrate solution produces silver and copper (II) nitrate solution. Write the chemical equation
Answer:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
Explanation:
We are to give the reaction expression for this displacement reaction.
Reactants = copper and silver nitrate solution
Products = silver and copper (II) nitrate
Copper = Cu
Silver nitrate solution = AgNO₃
Silver = Ag
copper (II) nitrate = Cu(NO₃) ₂
So:
Cu + 2AgNO₃ → 2Ag + Cu(NO₃)₂
How many protons, neutrons and electrons are there in a neutral Cesium atom?
55 protons, 78 neutrons, 55 electrons
69 protons, 100 neutrons, 69 electrons
37 protons, 37 neutrons, 45 electrons
43 protons, 65 neutrons, 43 electrons
Answer:
55 protons, 78 neutrons, 55 electrons
Explanation:
In a neutral Cesium atom we have 55 protons, 78 neutrons and 55 electrons. This can be found on the periodic table of elements.
Protons are the positively charged particles within an atom
Neutrons do not carry any charges.
Electrons are the negatively charged particles.
The amount of these subatomic particles can be obtained from the periodic table of element.
For a neutral atom, the number of protons and electrons are the same.
Since the atomic number is 55, it is also the number of protons in the atom.
What is water (H2O)? Select all that apply * an element a molecule 1 hydrogen and 2 oxygen 2 hydrogen and 1 oxygen
Answer:
2 hydrogen and 1 oxygen
Explanation:
H2O
Hydrogen has the coefficient so you multiply 1 by 2 and it equals 2
Oxygen does not have any sub or coe so its automatically 1
(a)A can of soda contains 12.0 fl oz. What is the volume in liters (given
that 1 L =
1000 mL)?
Answer:
0.355L
Explanation:
1fl oz (Fluid ounce) is an unit of volume widely used in United States of America. 1fl oz is equivalent to 29.5735mL.
12.0 fl oz are:
12.0fl oz * (29.5735mL / 1fl oz) = 354.9mL
There are 354.9mL in 12.0 fl oz.
As 1L = 1000mL, in 354.9mL you have:
354.9mL * (1L / 1000mL =
0.355L
What is the definition of momentum?
A- The amount of matter in an object.
B-Mass in motion.
C-Speed with direction.
D- The resistance to change motion
Answer:
B. Mass in motion. Is the definition of momentum
When an object is at rest ,we say forces are?
Answer:
If an object is at rest, then there are no forces acting on the object. It would take an unbalanced force to keep an object in motion at a constant velocity. It is the natural tendency of all objects to eventually come to a rest position.
Explanation:
Give 3 examples of conduction, radiation, and convection.
Answer:Conduction: Touching a stove and being burned. Ice cooling down your hand
Convection: Hot air rising, cooling, and falling (convection currents)
Radiation: Heat from the sun warming your face
Explanation:
Answer:
Radiation: Radio Waves, Conduction: An ice cube on a warm hand, Convection: A radiator
In _____ , materials move from an area of higher concentration to an area of lower concentration through a cell membrane.
1.selective permeability
2.active transport
3.passive transport
How many moles of oxygen are needed to produce 2 moles of Tetraphosphorus decaoxide (P4O10) in the reaction?
P4(s) + 5O2(g) →P4O10(s)
a. 1 mole
b. 0.2 moles
c. 10 moles
d. 5 moles
Answer:
C
Explanation:
5 moles of oxygen are needed to produce 1 mols of P4O10
x moles of oxygen are needed to produce 2 mols of P4O10
5/x = 1/2 Cross multiply
1*x = 2 * 5 Combine
x = 10
C
A. Airplanes typically fly at an altitude of about 10,000 meters. At this altitude the atmospheric pressure is significantly less than it is at sea-level. Because of this, airplane cabins must be pressurized so that the people on board can continue to get enough oxygen. If a typical 747 has a volume of 28,000 m3 and is filled with air at 101.3 kPa on the ground, what is the new volume of air inside when the cabin is pressurized to 75 kPa once it is in flight? b. Twinkies are made up of 68% air. If you buy a Twinkie in the airport and take it with you on a plane ride, how would its size change during the flight?
Answer:
The new volume of the air inside when the cabin is pressurized to 75 kPa is 37818.[tex]\overline 6[/tex] m³
Explanation:
The given 747 airplane parameters are;
The volume of air in the airplane, V₁ = 28,000 m³
The pressure of the air on the ground, P₁ = 101.3 kPa
The pressure of the air once it is in flight, P₂ = 75 kPa
Let V₂ represent the new volume of the air inside when the cabin is pressurized to 75 kPa
Boyle's Law states that the pressure of a given mass of air is inversely proportional to its volume at constant temperature
Therefore, by Boyle's law, we have;
P ∝ 1/V and P₁·V₁ = P₂·V₂
Which gives;
V₂ = P₁·V₁/P₂
Substituting the known values, we get;
V₂ = 101.3 kPa × 28,000 m³/(75 kPa) = 37818.[tex]\overline 6[/tex] m³
The new volume of the air inside when the cabin is pressurized to 75 kPa = V₂ = 37818.[tex]\overline 6[/tex] m³.
Calculate the molar mass of NaNO3-
What is the correct Lewis structure for a molecule of ammonia, NH3?
:-N-A
H-N-H
Н
H-NH