Answer:
Electrons at the outermost energy level of an atom are called valence electrons. They determine many of the properties of an element. That's because these electrons are involved in chemical reactions with other atoms. Shared electrons bind atoms together to form chemical compounds.
Explanation:
Answer:
electrons farthest from the nucleus of the atom. they are called valence electrons
In the article, Invasion of the Periodical Cicadas, why do scienctists believe that cicadas only reproduce every 13 or 17 years? Explain your answer with evidence from the text.
Hi, you've asked an incomplete question. However, I assumed you are referring to the article found on the Scientific American website.
Explanation:
Remember, according to that article we are told that scientists notice that these insects have a long nymphal (immature form before becoming adults) stage, one that can last up to 13 to 17 years on the ground before they leave the ground looking for mating partners.
Because it is only after mating occurs at this point that their eggs are laid, that is why scientists believe that cicadas only reproduce every 13 or 17 years.
What happens when A mixture of ammonia and oxygen is passed over platinum gauze heated to 800°C .
Answer:
The mixture forms nitrogen oxide and water upon reaction. However, 800 degree Celsius falls at higher limit of the process condition. It being an exothermic reaction, the reaction rate will be on the lower side than average.
You
2. An all natural mosquito repellent
is trying to make its way into the
market. One arm is sprayed with the
repellent and one arm is not sprayed
with anything. After 3 hours, the
number of mosquito bites is counted. What is the control group
Answer:
The arm that was not sprayed with anything
Explanation:
The control group would be the arm that was not sprayed with anything.
The control group during an experiment is a group that forms the baseline for comparison in other to determine the effects of a treatment. The control group does not include the variable that is being tested and as such, it provides the benchmark to measure the effects of the tested variable on the other group - the experimental group. In this case, the experimental group would be the arm that was sprayed with the repellent.
Carbon monoxide (CO) burns readily in oxygen (O2), forming
carbon Dioxide (CO2). Which of the follow equations is shows
this reaction and follows the law of conservation of mass?
Answer:
see attachment......
HeLlo, HeLp Me PleAsE, Ill MaRk YoU BrAiNlIeSt !
[tex]\huge\boxed{Option C}[/tex]
_____________________________________CALORIMETER:Calorimeter is device used for the measurement of heat. In a calorimeter we can use the temperature change of water to quantify an amount of heat. A calorimeter just captures all the energy released (or absorbed) by a reaction in the water. So Option A and B are wrong as calorimeter don't have anything to do with providing the heat or letting the the heat in, as it is the insulated calorimeter too.
_____________________________________Energy in the reaction:In the formation of any bond there is equal amount of heat required as to break that bond. It means Energy released in the making of bond is equal to the energy required in the breaking of the bond. So Option D is wrong as it says we need more energy in making then breaking.
_____________________________________Enthalpy:Enthalpy is the total heat content of the system. As we provide energy to the reactants and the product is formed, so The enthalpy(heat content) of product is more than the Enthalpy of the reactant, Thus Option C is correct.
Enthalpy is denoted by H or Q, its formula is,
H = U + PV
Where,
U is internal energy
PV is equals to Work done ; P = Pressure, V = Volume
_____________________________________Best Regards,'Borz'What is the formula for the compound formed when aluminum ions (Al3+) and chlorine ions (Cl-) unite?
A)AlCl
B)Al2Cl
C)AlCl2
D)AlCl3
Someone help me please i’ll give brainly
Answer:
Ionization
Melting
Vaporization
Explanation:
▶Ioniztion changes the charge of an electron, this usually happens between a chemical reaction. It takes a small amount of energy. Most of the time energy is absorbed instead of expelled!
▶ Melting changes the shape of the item and takes about 334 Joules/gram of energy.
▶ Vaporization changes the state of matter that the item is in and requires 2260 Joules/gram.
Brainliest is much appreciated! Hope I helped!
is xenon a metal and is Beryllium a metal
Answer:
No and yes
Explanation:
Xenon is a noble gas and beryllium is a metal
Answer: no and yes i also agree
Xenon is a noble gas and Beryllium a metal
Explanation:
The ocean both absorbs and releases heat more slowly than land does
True or false.
4x+15-3x+10= help me please
Answer:
7x+5
Explanation:
4x+15-3x+10
-10 -10
--------------------
4x+5-3x
+3x. +3x
---------------------
7x+5
2. The energy of motion is called
energy.
A. potential
B. electrical
C. chemical
D. kinetic
Answer:
Kinetic energy
Explanation:
Help plz!!!!!!!!!! Urgent
Answer:
Explanation:
10^-2
What causes metamorphic rocks to form from existing rocks?
O magma and minerals
O heat and pressure
O exposure to Earth's mantle
exposure
to Earth's surface
I think it's Heat and pressure
Answer:
heat and pressure did on edge
Explanation:
is this correct? and can you tell me yes or no for each one thanks
Answer: Yes it's correct.
Explanation: i hoped that helped!!
Answer:
yes this is correctly done
can someone tell me how I find the atomic radius of atoms and what they are. Thank youuuuuuuuu
Answer:
The radius of an atom can only be found by measuring the distance between the nuclei of two touching atoms and then halving that distance. Measuring the atomic radii of chemical elements is a complicated task as the size of an atom is of the order of 1.2×10-10 m. The electron cloud forming the shell of an atom does not have any fixed shape which makes it difficult to determine the atomic size of an atom. So we can say that practically we cannot determine the size of an individual atom.
Atomic Radius:
Atomic radius is the distance from the center of the nucleus to the outermost shell containing electrons.
Explanation:
The temperature T in Kelvin is 273.15 more than temperature C in degrees Celsius. Use your function to find the equivalent temperature in Kelvin for 100*C.
Answer:
T(K) = 373.15 K
Explanation:
The kelvin is the base unit of temperature in the International System of Units (SI). The symbol used to express temperature in kelvins is K.
The temperature of zero kelvins is called the absolute zero. It is considered to be the lowest possible temperature, although nothing has reached it. The absolute zero (0K) is - 273.15 degrees Celsius.
This is the equation we can use to solve this question:
[tex]T(K) = T(C) + 273.15[/tex]
We have 100*C.
[tex]T(C) = 100 C[/tex]
[tex]T(K) = 100C + 273.15[/tex]
[tex]T(K) = 373.15 K[/tex]
What is a chemical reaction
Are these correct?? Help please
What is the molarity of a hydrochloric acid solution, when 30.0 mL is neutralized by 48.0 mL of 0.100 mol/L
calcium hydroxide?
The molarity of a hydrochloric acid solution : 0.32 M
Further explanationTitration is a procedure for determining the concentration of a solution by reacting with another solution which is known to be concentrated (usually a standard solution).
Titrations can be distinguished including acid-base titration, depositional titration, and redox titration. An acid-base titration is the principle of neutralization of acids and bases is used.
Acid-base titration formula
Ma. Va. na = Mb. Vb. nb
Ma, Mb = acid base concentration
Va, Vb = acid base volume
na, nb = acid base valence
1 ⇒HCl (valence=1, HCl ⇒H⁺+Cl⁻, one H⁺)
2⇒Ca(OH)₂(valence=2, Ca(OH)₂⇒Ca²⁺+2OH⁻, two OH⁻)
M₂=0.1 M
V₂=48 ml=0.048 L
V₁=30 ml=0.03 L
[tex]\tt M_1.V_1.n_1=M_2.V_2.n_2\\\\M_1\times 0.03\times 1=0.1\times 0.048\times 2\\\\M_1=0.32[/tex]
8. An atom of element Z has the
electronic configuration 2.8.6. Which
one of the following statements
about element Z is correct? *
Answer:
See explanation
Explanation:
The question is incomplete but i will try to answer it to the best of my ability.
An element of configuration 2.8.6 is in group 16. This element will form a divalent anion Z^2-
Z is a nonmetal which combines with metals to form ionic bonds. Z can also react with other non metals to form covalent compounds.
Z is expected to have high electronegativity and electron affinity since it is a nonmetal of group 16.
The oxides of Z will dissolve in water to yield acidic solutions.
Consider the balanced equation below.
Upper P Upper C l Subscript 3 Baseline + Upper C l Subscript 2 Baseline right arrow Upper P Upper C l Subscript 5.
What is the mole ratio of PCl3 to PCl5?
Answer: The mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1: 1
Explanation:
According to the balanced chemical equation ,the number of atoms of each element has to be same on reactant and product side. The stoichiometric coefficients of the species represent their number of moles.
[tex]PCl_3+Cl_2\rightarrow PCl_5[/tex]
Thus in the reactants, there is 1 mole of [tex]PCl_3[/tex] and 1 mole of [tex]Cl_2[/tex] molecule. And thus there is 1 mole of [tex]PCl_5[/tex] in the product as well.
Thus the mole ratio of [tex]PCl_3[/tex] to [tex]PCl_5[/tex] is 1: 1
is soda homogeneous or heterogeneous?
Answer:
Thecinically it is both because and an un opened bottle of soda is homogeneous and an opened bottle of soda is herterogeneous. I hope this helps please reward branlist.
Is PH3 polar or nonpolar
Phosphine is an example of a polar molecule with non-polar bonds
1. Glucose, a type of sugar, has the formula
CH, O. What is the total number of atoms
in one molecule of glucose?
Answer:
The answer is 24 in total
Explanation:
This is a 2:1 ratio. The formula of it is C6 H12 O6
in any study of energy, energy conversion is not important. true false
Answer:
I think its false
Explanation:
Any energy is important
Hope this helps <3
Answer:
In any study of energy, energy conversion is not important. Heat energy that is lost cannot usually be used to produce work.
Explanation:
Hope this helps!
If so, please mark BRAINLIST!!
thx
According to the diagram which statement best describes what happens when two astronauts collide in space? Will give crown!!!!
Answer:
J. Their momentum is conserved
Explanation:
According to the diagram, the best statement that describes what happens when two astronauts collides in space is that their momentum is conserved.
The momentum before collision is 320kgkm/hr and after collision it is 320kgm/s
This collision is an inelastic collision;
momentum before = momentum after
m₁v₁ + m₂v₂ = v(m₁ + m₂)
m₁ = 80kg
v₁ = 4km/hr
m₂ = 80kg
v₂ = 0
v = 2km/hr
Insert the parameters;
(80 x 4) + (80 x 0) = 2(80 + 80)
320 = 320
When their is a new moon the sun and moon are on the same side of the earth this leads to a combination of gravitational forces causing usually high tides called
Neap tides
Low tides
Supreme tides
Spring tides
Answer:
Low Tides
Explanation:
Took the test
100%
explain why particles of colloidal solution donot settle down when left undisturbed , while in the case of suspensions they do .?
Answer:
the partial of colloidal are smaller and they are not heavy whereas the partial of suspension are larger but they are heavy and less movement thus they settle down due to gravity
Sodium thiosulfate mixed with hydrochloric acid makes a green precipitate is this a physical or chemical change?
a. Physical
b. Chemical
Can someone help me answer this I will give you brainliest
Answer:
I don't know the answer you can search it on Google you will get it and don't forget to follow me and mark me as brainlest please I will follow u back really if u follow me back
Answer:
It is chemical Change
Explanation:
Because you are changing the substance.
If a sample of nitrogen gas is compressed to fit in a smaller container, what happens to the
pressure, assuming the temperature remains constant?
Answer:
The pressure increases
Explanation:
In this action it is best to apply Boyle's law to resolve the problem. This is an interplay between Volume, Pressure and Temperature.
According to Boyle's Law "the volume of a fixed mass of a gas varies inversely as the pressure changes, if the temperature is constant". Since the volume is being reduced to cram into the container, the pressure of the gases increases. In the smaller container, pressure rises and the volume reduces if temperature remains constant.