Answer:
More than 50% of the 100 billion stars in the Milky Way galaxy have at least one planet orbiting.
Explanation:
This is False so this would be your Answer
Answer: planets orbiting stars in the habitabke zone are likely to have life existinv on them
Explanation:
because it is false and i took the quiz
What is the value of index fossils to the fossil record?
How can electronegativity be used to explain the reaction we see in terms of the numbers and types of bonded being formed in lithium?
Explanation:
Lithium is an electropositive element that readily loses electrons.
Oxygen is electronegative and it will readily accept electrons.
Due to this significant electronegativity differences between the two species they form electrovalent or ionic bonds between them.
2atoms of Li lose two electrons:
Li → Li²⁺ + e⁻
Lithium isoelectronic with helium
For oxygen;
O + 2e⁻ → O²⁻
Oxygen is isoelectronic with Neon
Two ions of the lithium combines with the oxygen to form the bond;
4Li + O₂ → 2Li₂O
The electrostatic attraction between the two ions forms the ionic bond
define open and closed circuit
Answer:
An open circuit is one where the continuity has been broken by an interruption in the path for current to flow. A closed circuit is one that is complete, with good continuity throughout. A device designed to open or close a circuit under controlled conditions is called a switch.
Isopentyl acetate is the molecule largely responsible for the aroma and taste of bananas. It is made up of carbon, hydrogen, and oxygen. Combustion of a 3.256-g sample of isopentyl acetate produces 7.706 g CO2 and 3.156 g H2O. Using these results, what is the correct empirical formula for isopentyl acetate?
Answer:
Explanation:
7.706 g of CO₂ will contain 12 x 7.706 / 44 g of C
= 2.1 g of C .
This will be contained in 3.256 g of isopentyl acetate
3.156 g of H₂O will contain 2 x 3.156 / 18 g of H
= .351 g of H
This will be contained in 3.256 g of isopentyl acetate
Rest will be oxygen
amount of oxygen in 3.256 g of isopentyl acetate
= 3.256 - ( 2.1 + .351 )
= .805 g
ratio of C , H , O in isopentyl acetate
= 2.1 g : .351 g : .805 g
2.1 / 12 : .351 / 1 : 0.805 / 16 ratio of moles
= .175 : .351 : .05 ratio of moles
= 3.5 : 7.02: 1
= 7 : 14 : 2
empirical formula of isopentyl acetate
= C₇ H₁₄ O₂ .
To pass a test with 15 questions how many can I get wrong?
Answer:
You can get 7 answers wrong.
Explanation:
Let's calculate the average
[tex]\frac{15}{2} \\\\=7.5[/tex]
So if you correctly answer 8 -15 (7.5 is approximated to 8 )questions correctly you will pass.
So you can get 7 answers wrong.
Why do you think Earth's plates move on the surface?
Explanation:
heat in the Earth's core
The ____ energy of an object increases with its height.
Thermal
Chemical potential
Gravitational Potential
kinetic
Answer:
chemichal potential
Explanation:
Answer:
Gravitational Potential
A divalent metal oxide contains 60 % of metal. What is atomic weight of metal ?
Atomic weight of metal : 24
Further explanationProust states the Comparative Law that compounds are formed from elements with the same Mass Comparison so that compounds have a fixed composition of elements
Divalent metal oxide=XO
MW O = 16
MW XO₂ = X+16
[tex]\tt \%mass=\dfrac{Ar~X}{X+16}\times 100\%\\\\0.6=\dfrac{X}{X+16}\\\\0.6(X+16)=X\\\\0.6X+9.6=X\\\\0.4X=9.6\rightarrow X=24[/tex]
HELP!
A. W
B. X
C. Y
D. Z
Answer:
B
Explanation:
Lithium has two isotopes, lithium-6 weighing 6.015 amu (7.5% abundance), and lithium-7
weighing 7.016 amu (92.5% abundance). What is the atomic mass of lithium?
with calculations
Answer:
The answer is 6.941 but I dont really have the explanation
Explanation:
The atomic mass of lithium will be 6.9458 amu.
What is Atomic Mass ?
The mass of an atom of a chemical element expressed in atomic mass units.
It is approximately equivalent to the number of protons and neutrons in the atom (the mass number) or to the average number allowing for the relative abundances of different isotopes.
Calculation :
Consider 10000 atoms of Li ;
742 of them would have mass 6.02.9258 of them would have mass 7.02.
Hence,
The total mass of these 10000 Li atoms would be ;
(742 × 6.02) + (9258 × 7.02) = 69458
∴ 1 Li atom on average would have mass = 69458 / 10000 = 6.9458 amu
Therefore, The atomic mass of lithium will be 6.9458 amu.
Learn more about Atomic Mass here ;
https://brainly.com/question/17067547
#SPJ2
Which of the following statements are incorrect?
A. A sodium atom has a smaller radius than a potassium atom.
B. A neon atom has a smaller radius than an oxygen atom.
C. A fluorine atom has a smaller first ionization energy than an oxygen atom.
D. All are statements are incorrect
b is the answer because oxyen atom has a smaller radius
Answer: B
Explanation:
What is a rule for determining the mass number of an atom or ion?
Answer:
The mass number of the atom is equal to the sum of the number of protons and neutrons in the nucleus
Explanation:
Each proton and each neutron weigh one amu( atomic mass unit), adding together the neutrons and protons and multiplying by 1 amu you get the mass of an atom
What is the formula for mass number?
Answer:
the formula for mass number is "mass number = protons + neutrons".
argon is an inert gas give reason.
Answer:
You're right
Argon is an inert gas.
Explanation:
Answer:
Argon is in zero group and it has octet structure so argon will not react with any compound
How do slab pull forces affect plate motion? Choose the correct answer.
Uplifted mantle causes plates to move apart.
Convection currents drive the plate downward to move it.
Earthquakes break the crust into smaller plates to make motion easier.
The weight of the subducted plate produces a force to continue moving the plate.
Answer:
The weight of the subducted plate produces a force to continue moving the plate.
Explanation:
3. Which element is a nonmetal? *
1 point
Nitrogen (N)
Iron (Fe)
Titanium (Ti)
Potassium (K)
Which is the best description of a molecule?
Answer:
A molecule is the smallest particle in a chemical element or compound that has the chemical properties of that element or compound. Molecules are made up of atoms that are held together by chemical bonds. These bonds form as a result of the sharing or exchange of electrons among atoms.
Answer:
C
Explanation:
How are oxidation states of transition metals indicated in the names of metal
compounds?
A. Prefixes are used to indicate oxidation states.
B. Group numbers are used to indicate oxidation states.
C. Roman numerals are used to indicate oxidation states.
D. Subscripts are used to indicate oxidation states.
Answer:
The anser is c
Roman numerals are used to indicate oxidation states. Hence, option C is correct.
What is the oxidation state?An oxidation state is a number given to the atom of an element when participating in a chemical reaction.
Roman numerals are used to indicate oxidation states of transition metals.
The names for transition metal compounds often have roman numerals in them, because the roman numerals indicate the charge on the transition metal. But the oxidation state of Cu in CuO is +2, and the oxidation state of Cu in [tex]Cu_2O[/tex] is +1. Name metal first and charge and transition metal with a roman numeral.
The transition metals may form more than one ion, thus it is needed to be specified which particular ion we are talking about. This is indicated by assigning a Roman numeral after the metal. The Roman numeral denotes the charge and the oxidation state of the transition metal ion.
[tex]Fe^{2+}[/tex] would be named iron (II) and [tex]Fe^{3+}[/tex] would be named iron (III).
Hence, option C is correct.
Learn more about the oxidation state here:
brainly.com/question/11313964
#SPJ2
Using dimensional analysis, how many kilometers are there in 34 inches?
Answer:
There are many ways to figuring this out: you could use a ruler, a calculator or scrap paper.
Explanation:
This is not an actual flat out answer, but it’s helpful methods to getting the answer the next time you are stuck. Hope you are having a nice day. Bless your heart and soul.
I will pick the brainiest answer! Thanks! :)
1. What is volume displacement? Why would you use this method?
2. What is density? What happens to things that are denser? What happens if they are less dense?
Answer:
1. The volume of displaced fluid is equivalent to the volume of an object fully immersed in a fluid or to that fraction of the volume below the surface of an object partially submerged in a liquid. The weight of the displaced portion of the fluid is equivalent to the magnitude of the buoyant force.
Why would you use this method?
So it can be used to accurately measure the volume of the human body and other oddly shaped objects by measuring the volume of fluid displaced when the object is submerged.
2. Density, mass of a unit volume of a material substance. The formula for density is d = M/V, where d is density, M is mass, and V is volume. Density is commonly expressed in units of grams per cubic centimetre.
What happens to things that are denser?
Students should realize that if an object weighs more than an equal volume of water, it is more dense and will sink, and if it weighs less than an equal volume of water, it is less dense and will float.
What happens if they are less dense?
The density of an object determines whether it will float or sink in another substance. An object will float if it is less dense than the liquid it is placed in. An object will sink if it is more dense than the liquid it is placed in.
7th grade help me plzzzzzzzz
Answer:
1. Metals
2. Solid, gas, liquid
Explanation:
For #1:
The majority of elements in the periodic table are classified as metals. The transition metals lie in the center of the table, spanning groups three through 12. These elements are solid at room temperature, except mercury, and have the metallic color and malleability expected of metals.
Hope this helps :)
How much eat is absorbed when 50.0g of water changes from 25.0 Celsius to 37.0 Celsius?
What part of the earth are the plate tectonics on?
lithosphere
outer core
asthenosphere
inner core
HELP ME PLEASE!!! I NEED THIS OR I WILL FAIL!!!
Answer:
replacement
Explanation:
Because the No and The Ci switch but it might not be the answer but I know that they have to switch and replacement sounds like the best answer
Answer:
Oxidation
Explanation:
Hope this helps :)
GIVING BRAINLY, FOLLOW, 5 STARS AND HEARTS
which of the following is NOT a characteristic of hot water heating systems?
Answer:
The one on the top,'' As the water cool, it is returned to the boiler where it is heated,''
Explanation:
Help! I am in a hurry! Will get brainliest if correct!
Answer:
nonmetel
Explanation:
Answer:
Its a non-metal
Explanation:
Elements that tend to gain electrons to form anions during chemical reactions are called non-metals. These are electronegative elements. They are non-lustrous, brittle and poor conductors of heat and electricity (except graphite). Non-metals can be gaseous, liquids or solids.
Consider the equation:
Ca+O2→CaO
What needs to be done in order to balance the equation?
Place a 2 in front of the Ca and the CaO.
Place a 2 in front of the O2 and the CaO.
Place a 2 in front of the CaO only.
Place a 2 only in front of the Ca.
help please I will give brainliest to the best answer
Answer:
the correct answer is D
If 0.484J of heat is added to 0.1372g of water, how much will the temperature increase?
0.263 °C
0.927 °c
0.843 °C
0.460 °C
Answer:
ΔT = 0.843 °C
Explanation:
Given data:
Heat added = 0.484 J
Mass of water = 0.1372 g
Temperature increase = ΔT = ?
Solution:
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
Specific heat capacity of water is 4.184 j/g.°C
Now we will put the values in formula.
0.484 j = 0.1372 g × 4.184 j/g.°C× ΔT
0.484 j = 0.574j/°C× ΔT
ΔT = 0.484 j / 0.574j/°C
ΔT = 0.843 °C
Why are supergiant so bright?
Because supergiants are so massive, the core temperature gets much hotter than in giants, so supergiants can fuse elements heavier than hydrogen and helium. But to support their tremendous mass, supergiants burn up their fuel much more quickly.
Answer:
because the core tempature gets much hotter.
Explanation:
so supergiants can fuse elements heavier than hydrogen and helium. But to support their tremendous mass, supergiants burn up their fuel much more quickly.