Answer:
it would be the second one thank me later
Explanation:
What does an atom's period tell us?
Select one:
a. Number of protons
b. Number of shells
c. Number of valence
electrons
d. Number of electron
A reaction that had two compounds as reactants and two compounds as products is most likely a
double-replacement reaction
Write the chemical formulas and names for the following ionic compounds. Tin4+ and chlorine
Answer:
SnCl4.
Explanation:
What for a neutral element is [Kr] 4d8 5s2 ?
Answer:
1.Hydrogen: 1s1 2 - Helium: 1s2
45 – Rhodium: [Kr], 5s2, 4d7 46 – Palladium: [Kr], 5s2, 4d8
47 – Silver: [Kr], 5s2, 4d9 48 – Cadmium: [Kr], 5s2, 4d10
49 – Indium: [Kr], 5s2, 4d10, 5p1 50 – Tin: [Kr], 5s2, 4d10, 5p2
Thus 43 electrons, so the neutral atom has atomic number 43. Look at a periodic table and you see that this element is technetium.
Element Atomic Number Element Symbol Element Electron Configuration
45 Rh [Kr] 4d8 5s1
46 Pd [Kr] 4d10
47 Ag [Kr] 4d10 5s1
48 Cd [Kr] 4d10 5s2
A sample of ethanol (C2H6O) has a mass of 0. 2301 g. Complete combustion of this sample causes the temperature of a bomb calorimeter to increase by 1. 33°C. The calorimeter has a mass of 2. 000 kg and a specific heat of 2. 45 J/g•°C. What is the heat of combustion for this sample? kJ.
The heat of combustion of the sample is calculated to be -1300 kJmol-1.
We know that energy is neither created nor destroyed but is converted from one form to another. The heat lost by the ethanol when it is burnt is equal to the heat gained by the calorimeter.
Heat gained by calorimeter = 2.×10^3 g × 2. 45 Jg-1°C-1 × 1. 33°C
= 6.5 kJ
Number of moles of ethanol = 0. 2301 g/46 g/mol = 0.005 moles
Heat of combustion of the sample = -( 6.5/0.005 moles) = -1300 kJmol-1
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1. what property of gas does not change?
2. Name two gases besides oxygen found in Earth's atmosphere
Answer:
hydrogen and nitrogen or something?
Explanation:
Answer:
nitrogin and i forgot the other one srry!!
Explanation:
1. While on a movie set, a stuntman jumps off
the roof of a building. As he falls toward an
airbag, what is increasing?
A. gravity
B. wind velocity
C. kinetic energy
D. potential energy
kinetic energy kkkkkkkkkk
which of the following atom could reside in the same group? Explain your answer
The pH scale is used to tell if a substance
is an acid or base. Substances with a pH
of 7 are neutral. An acid is anything
below 7 and a base is anything above
7.What would a household cleaner with a
pH of 10 be considered on the pH scale?
Answer:
Explanation:
pH > 7 as 10 is more than 7
The cleaner is very corrosive.
It is a moderately basic. If it was 12 that would make it much more basic (100 times more basic).
an atom of which of the following elements can form the most bonds?
a. phosphorus
b. sodium
c. oxygen
d.oxygen
In the first half of the citric acid cycle, ____________ is oxidized, yielding a pair of electrons that reduce a molecule of NAD to NADH.
Answer:
isocitrate
Explanation:
Hellpppppppppppppppppppppp
Answer:
SnH4
Explanation:
Because the melting point of SnH4 is higher than CH4
which statement describes how vapor pressure occurs? (1 point)
a) Some molecules of a substance have high enough kinetic energy to vaporize. These molecules exert
pressure on the substance.
b) Some molecules of a substance have low enough kinetic energy to melt. These molecules exert pressure on the substance
c) Some molecules of a substance have low enough kinetic energy to vaporize. These molecules exert
pressure on the substance.
d) Some molecules of a substance have high enough kinetic energy to melt. These molecules exert pressure on the substance
Some molecules in a substance have a high kinetic energy hence they are able to convert into vapor. These molecules exert pressure on the liquid surface.
We know that the molecules that compose matter are in constant random motion. The kinetic energy of all the molecules in the liquid are not the same. The molecules at the surface of the liquid posses more kinetic energy than the molecules below.
Some molecules of a substance have high enough kinetic energy to vaporize. These molecules exert pressure on the substance.
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Answer:
Some molecules of a substance have high enough kinetic energy to vaporize. These molecules exert pressure on the substance.
Explanation:
The density of iron is 7.0 g/cm'. What volume of iron would have a mass of 14.0 g?
Answer:0.284ib/in 3
Explanation:
[tex]\text{Given that,}\\\\\text{Density of iron, }~ \rho = 7 ~\text{g cm}^{-3} = 7 \times 10^{3}~ \text{kg m}^{-3}\\\\\\\text{Mass, m =14 g =} ~ 14 \times 10^{-3} ~\text{kg}\\\\\\\text{Volume of iron,}~ V = \dfrac{m}{\rho} = \dfrac{14 \times 10^{-3}}{7\times 10^{3}} = 2 \times 10^{-6} ~~ m^3[/tex]
how do i set up an electron configuration
Answer:
Electron configuration can be carried out in two steps which can be:
Sublevel notation
Shell notations.
In the sublevel notation, the sequence of filling electrons into the orbitals of the sublevels are guided by some principles:
the maximum number of electrons in the orbital of sublevels are two for s-sublevel, six for p-sublevel, ten for d-sublevel and fourteen for f-sublevel. This indicates that the maximum number of electrons in an orbital is two.
Aufbau's prinicple states that sublevel with lower energies are filled up before those with higher energies.
Pauli exclusion principle states that no two electrons in an atom can have the same set of the four quantum numbers.
Hund's rule states that electrons go into degenerate orbitals singly first before pairing occurs.
Using the shell notation, numbers are used to denote the sum of electrons in all orbitals each energy level.
For an atom of Be:
Sublevel notation for the 4 electrons 1s²2s²
Shell notation 2,2
Other representation is using the electron dot structure.
1. How many covalent bonds can nitrogen form?
2. Which of the following represents a covalent compound?
A. O2
B. CO2
C. Cl2
D. NaCl
3. 2. Nitrogen is a diatomic element with five valence electrons. Create a model of a molecule of nitrogen.
Answer:
1. 3 covalent bonds
2. CO2
Nitrogen can form three covalent bonds and carbon dioxide represents a covalent compound.Molecule of nitrogen is attached in image below.
What is a covalent bond?Covalent bond is defined as a type of bond which is formed by the mutual sharing of electrons to form electron pairs between the two atoms.These electron pairs are called as bonding pairs or shared pair of electrons.
Due to the sharing of valence electrons , the atoms are able to achieve a stable electronic configuration . Covalent bonding involves many types of interactions like σ bonding,π bonding ,metal-to-metal bonding ,etc.
Sigma bonds are the strongest covalent bonds while the pi bonds are weaker covalent bonds .Covalent bonds are affected by electronegativities of the atoms present in the molecules.Compounds having covalent bonds have lower melting points as compared to those with ionic bonds.
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#SPJ6
7. Describe the difference between a genetically modified organism (GMO) and an unmodified organism.
Answer:
there
Explanation:
organic food is farmed and manufactured per the guidelines put forth by the Department of Agriculture. Organic food is typically pesticide-free, GMO-free, and sustainably farmed.
Non-GMO food, or non-genetically modified food, has not been altered or engineered in any way. Non-GMO food doesn’t necessarily adhere to the same guidelines that organic food does.
GMO food has been genetically modified in some form, usually in a laboratory.
carbon-14 has a half-life of 5,730 years. how long will it take for 112.5 g of a 120.0-g sample to decay radioactively?
Answer:
It will take 22920 years to decay 112.5 g of 120 grams.
Explanation:
A student creates a hypothesis about their upcoming experiment. What must the
student do in their experiment with relationship to their hypothesis?
create a law based on the hypothesis
change the experiment to make the hypothesis correct
ignore the hypothesis
make observations to prove or disprove the hypothesis
Answer:
D. make observations to prove or disprove the hypothesis
Explanation:
ow does the food chain start? A Plant life uses energy from the sun to make food. B Insects like grasshoppers eat plant life. C Animals like rats eat insects. D Humans eat large animals and plant life
How many moles of nitrogen dioxide, NO2, are present if the reaction conditions are 330 K, 2.46 atm, and 4.8 L
There are 0.436 moles of nitrogen dioxide, NO2, present if the reaction conditions are 330 K, 2.46 atm, and 4.8 L.
IDEAL GAS LAW:The number of moles of nitrogen dioxide (NO2) in this question can be calculated by using the ideal gas law equation as follows:
PV = nRT
Where;
P = pressure (atm)V = volume (L)T = temperature (K)R = gas law constant (0.0821 Latm/molK)n = number of molesAccording to the reaction conditions given in this question;
P = 2.46 atmV = 4.8Ln = ?T = 330K2.46 × 4.8 = n × 0.0821 × 330
11.81 = 27.093n
n = 11.81 ÷ 27.093
n = 0.436mol
Therefore, there are 0.436 moles of nitrogen dioxide, NO2, present if the reaction conditions are 330 K, 2.46 atm, and 4.8 L.
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Which of the following is the strongest covalent bond?
Single bond
Double bond
Triple bond
Hydrogen bond
Answer:
Triple bond is the strongest bond
Triple bonds are stronger than the equivalent single bonds or double bonds, with a bond order of three.
Answer:
single bond.In a single covalent bond, when the electrons are shared between two s orbitals, the resulting bond is a sigma (σ) bond . Sigma bonds are the strongest covalent chemical bonds....!!
now imagine that you have analyzed an additional vntr. from the blot below, what is the expected frequency of occurrence?
How many oxygen atoms
in a molecule of table sugar (C12H22011)?
ОА 45
ООО
В. 22
с 12
Op. 11
SUBMIT
Answer:
6.6242 x 10 ^ 24
Explanation:
This is the correct answer because you know there is 11 oxygen moles in 1 mole of sugar so using dimensional analysis you can solve it. You start will 11 moles of oxygen, and multiply by Avogadro's number(6.022 x 10 ^23) to get the amount of atoms. I don't see it as an answer, but I am confident in this, so I would ask your teacher specifically.
Hope this helps!
In Natural selection, who/what makes the decision about which traits are desirable and get passed to future generations?
please need help asap thank you.
Answer:
Different alleles and genes determine what gets passed down.
Explanation:
Its a pretty weird/ open ended question, but the alleles that help an organism survive, will be passed down more often because they are more "fit" and can out survive its competitors within a certain species.
how many molecules are in 122 grams of Cu(NO3)2
Answer:
3.917 x 10 ^ 23
Explanation:
You just want to use dimensional analysis to solve. So first start with 122g of copper(II) nitrite, and divide by the molecular weight to get it into moles. Then you know that 1 mole = 6.022 x 10 ^23 molecules (Avogadro's Number) so multiply that by your current moles. A hint for these problems always convert what you were given to moles since it is easy to get to a lot of things through them. ** Use the molar mass/molecular weight for going from grams to moles or moles to grams and use Avogadro's number when going from moles to atoms/molecules or reverse.
Hope this helps!
HELLLPPPP ASAP !!!! Pls
Answer:
Melting point, boiling point, state of matter at room temperature, heat of vaporization, flammability and reactivity
Explanation:
Select all the correct answers.
In the cathode ray tube experiment, J.J. Thomson passed an electric current through different gases inside a cathode ray tube in the presence of
an electric field. In which two ways did this experiment change scientists' understanding of the atom?
O It showed that atoms combine in different proportions.
O It showed that atoms can be divided into smaller parts.
M It showed that all atoms of the same element are similar.
D
It showed that individual atoms could be destroyed
showed that all atoms contain electrons.
The two ways the cathode ray tube experiment changed scientists'
understanding of the atom was it showing that atoms can be divided into
smaller parts and all atoms contain electrons.
J.J Thompson was the scientist which performed the cathode ray tube
experiment and was able to ascertain it was negatively charged as a result
of it being deflected to the positive electrode.
His observation showed that the atoms contain sub-atomic particles called
electrons which are negatively charged.
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7) Element Families on the Periodic Table have similar _____________________. There are ________ Families.
8) Alkali Metals are good conductors of _____________________________ and ________________________________.
9) There are a total of _________ elements that are grouped as Transition Metals.
10) As opposed to metals, non-metals can be very __________________________. They have no metallic ____________
and do not reflect ______________________.
11) All Lanthanide Series elements occur naturally except for ___________________________________.
12) All Actinide Series elements are ___________________________ and most are _____________________
The periodic table is composed of metals and nonmetals arranged in groups and periods.
The periodic table is an arrangement of elements in groups and periods based on their properties. The properties of elements repeat at regular intervals hence the term, "periodic".
The answers to the questions are;
7) Element Families on the Periodic Table have similar properties. There are 18 families.
8) Alkali Metals are good conductors of heat and electricity.
9) There are a total of 38 elements that are grouped as Transition Metals.
10) As opposed to metals, non-metals can be very opaque. They have no metallic luster and do not reflect light.
11) All Lanthanide Series elements occur naturally except for promethium.
12) All Actinide Series elements are radioactive and most are synthetic.
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This chemical equation is balanced.
F2 + 2NaBr
2NaF + Br2
How does the balanced chemical equation show the conservation of matter
in this chemical reaction?
A. There are fewer Na atoms in the reactants than in the products.
B. The number of Fatoms in the reactants equals the number of F
atoms in the products.
C. The compound NaF is a substance that is different from the
compound NaBr.
D. There are more Br atoms in the reactants than in the products.