Answer:
to help
Explanation:
to help
Which of the following describe glands? Check all that apply.
a structure that secretes substances through a duct
a thin layer that separates or connects structures inside the body
a structure that secretes hormones into the bloodstream
a structure usually made from connective and epithelial cells
Answer:a, c, d
Explanation: just did it on edge
Helppppppp plssss guysss
Answer:
3 - coefficient
2 subscripr
6 total #
cl- element symbol
Radio waves are examples of electromagnetic waves. T or F
Answer:
the answer is true
Explanation:
10. What are the upper and lower extremes of
the moisture content of wood?
Isotopes have
Question 1 options:
A)
different numbers of both protons and neutrons in their nuclei.
B)
a different number of neutrons in their nuclei.
C)
a different number of protons in their nuclei.
D)
a different number of electrons.
Question 2 (5 points)
An aqueous solution
Question 2 options:
A)
must contain three or more substances.
B)
is a single-phase heterogeneous mixture.
C)
has water as the solvent.
D)
has water as the solute.
Question 3 (5 points)
Which of the following is a homonuclear diatomic molecule?
Question 3 options:
A)
NH3
B)
CO
C)
2CO2
D)
H2
Question 4 (5 points)
Given a container of a solution of 5% HCl, all samples tested from this same bottle will have the same mass ratio of hydrogen to chlorine. This is an application of
Question 4 options:
A)
the law of conservation of energy.
B)
the law of multiple proportions.
C)
the law of conservation of mass.
D)
the law of constant composition.
Question 5 (5 points)
Elements in the same period
Question 5 options:
A)
have the same principal quantum number.
B)
form bonds with the same type of elements.
C)
have the same number of valence electrons.
D)
have the same number of protons.
Answer:
question 1 answer is b
Explanation:
istopes equal to same atomic number but different mass number
Which of the following is the metric system based on?
Help me this, I only have 10 minutes to answer!!!!
Answer:sedimentary
Explanation:
I really need help on this
..
Answer:
b
Explanation:
How many elements are shown in the diagram below for Hydrogen Peroxide?
Ten
Seven
Four
Two
Answer:4
Explanation:
4
What is the unbalanced force on a 1/2 kg object that causes it to accelerate 3 m/s2 to the right
Answer:
The answer is 1.5 NExplanation:
The force acting on an object given it's mass and acceleration can be found by using the formula
force = mass × accelerationFrom the question we have
force = 0.5 × 3
We have the final answer as
1.5 NHope this helps you
The temperature at which a liquid becomes a gas is the
point.
O A) freezing
O B) boiling
O C) condensation
O D) melting
Answer:
Boiling
Explanation:
What of the following is made out of atoms? (HINT: vocabulary word "atom" or "matter") * 1 Air
2 Light
3 Energy
4 Sound
16. The diffusion rate of an unknown gas is measured to be 31.50 mL/min. Under
identical conditions, the diffusion rate of oxygen gas is measured to be 30.50
mL/min. Hint: diffusion rate is directly related to velocity.
Determine the identity of the unknown gas from the following options:
a. CH4
b. CO
C. NO
d. CO2
e. NO2
Answer:
Explanation:
[tex]\frac{r_1}{r_2} = \sqrt{\frac{M_2}{M_1} }[/tex]
r₁ and r₂ are rate of diffusion of gas having molecular mass of M₁ and M₂
[tex]\frac{31.5}{30.5} = \sqrt{\frac{32}{M_1} }[/tex]
1.0666 = 32 / M₁
M₁ = 30
molecular weight of NO = 14 + 16 = 30
So the unknown gas is NO .
How many grams of glycine amide should be added to 1.00 g of glycine amide hydrochloride to give 100 mL of solution with pH 8.00
Answer:
0.4235 g of glycine amide should be added
Explanation:
From the given information:
The equation of the reaction can be illustrated as:
[tex]BH^+ \to B^+ + H ^-[/tex]
where:
mass of glycine amide hydrochloride = 1.00 g
Suppose x be the amount of (in grams) of glycine amide that is required to be added; Then:
[tex][BH^+] = \dfrac{1.00 \ g}{110.54 \ gmol \times 0.100 L}[/tex]
[tex][BH^+]=[/tex] 0.0905 M
So, For [B} i.e, for glycine amide
[tex][B] = \dfrac{x \ g}{74.083 \ gmol \times 0.100 L}[/tex]
[B] = 0.135x M
∴
[tex]\dfrac{[B]}{[BH^+]}=\dfrac{0.135x \ M}{0.0905 \ M }}[/tex]
[tex]\dfrac{[B]}{[BH^+]}=1.49x[/tex]
The log of the above question can be computed as:
[tex]log _{10}\dfrac{[B]}{[BH^+]}=log _{10}1.49x[/tex]
[tex]pH = pK_a + log _{10} \dfrac{[B]}{[BH^+]}[/tex]
8.00 = 8.20 + [tex]log _{10}(1.49x)[/tex]
8.00 - 8.20 = [tex]log _{10}(1.49x)[/tex]
-0.20 = [tex]log _{10}(1.49x)[/tex]
1.49 x = [tex]10^{-0.20}[/tex]
1.49 x = 0.631
x = 0.631/1.49
x = 0.4235 g
Consider the following statements about first ionization energies:
I. Because the effective nuclear charge for Mg is greater than that for Be, the first ionization energy of Mg is greater than that of Be.
II. The first ionization energy of O is less than that of N because in O we must pair electrons in the 2p orbitals.
III. The first ionization energy of Ar is less than that of Ne because a 3p electron in Ar is farther from the nucleus than a 2p electron in Ne.
Which of the statements I, II, and III is or are true?
Answer:
I,II, III
Explanation:
Firstly, the magnitude of nuclear charge affects the first ionization energy of an element. Hence,as effective nuclear charge increases, the attraction between the nucleus and the outermost electron increases and ionization energy consequently increases. Thus Mg has a higher first ionization energy than Be.
Secondly, oxygen has an electron configuration of 1s2 2s2 2p4 while nitrogen has an electron configuration of 1s2 2s2 2p3. Now, recall that extra energy is often associated with half filled orbitals hence nitrogen has a higher first ionization energy than oxygen. Furthermore, the addition of electron to an already half filled 2p orbital in oxygen (pairing) leads to inter electronic repulsion and drastic fall in first ionization energy. Therefore, as we move from nitrogen to oxygen in the periodic table, greater inter-electron repulsion between two electrons in the same p-orbital counter balances the increase in effective nuclear charge hence nitrogen has a greater first ionization energy than oxygen.
Lastly, the 3p orbital is far away from the nucleus hence we expect it to feel less of nuclear attraction than a 2p orbital. Hence the first ionization energy of Ar is less than that of Ne.
what is the energy level of aluminum
Answer:
Three energy levels
The Bohr model for aluminum shows its thirteen protons and neutrons inside the nucleus, with thirteen electrons orbiting in three energy levels.
1. Which of the following pairs of elements is most likely to share one or more pairs of electrons between
their nuclei?
a. Lithium and iodine
b. Sodium and lead
c. Copper and oxygen
d. Sulfur and chlorine
Answer:
d. Sulfur and chlorine.
Explanation:
A covalent bond is formed by two non-metals with similar electronegativities. As a consequence, they share one or more pairs of electrons between their nuclei.
Which of the following pairs of elements is most likely to share one or more pairs of electrons between their nuclei?
a. Lithium and iodine. NO. Lithium is a metal and iodine a non-metal.
b. Sodium and lead. NO. Both sodium and lead are metals.
c. Copper and oxygen. NO. Copper is a metal and oxygen is a non-metal.
d. Sulfur and chlorine. YES. Both are non-metals.
how did domestication of early crops start?
Answer:
In the Fertile Crescent in the Middle East, cereal crops were first domesticated about 11,000 years ago. Generally, the first domesticated crops were annuals with big seeds or fruits. ... Humans began to transition from a hunter-gatherer culture to a settled farming society as domestication took place.
Please mark me brainliest!
Hope this helps God bless!
what is the hybridization of NO2
Answer: Explanation:
If we apply the hybridization rule then it states that if the sum of the number of sigma bonds, lone pair of electrons and odd electrons is equal to three then the hybridization is sp2.
14. Identify the type of reaction: Pb + 2 AgCl → 2 Ag+ PbCl2
a. Combination/synthesis
b. Decomposition
c. Double replacement
d. Single replacement
I would like some help on this please.
Answer:
Both b and c i think so... .
I think it is the dark blue tile because if it is not soluble, or insoluble, then it will not dissolve and you will still see it floating around in the liquid or at the bottom of the container.
Which of the following is not a size-independent property of matter?
O volume
O boiling point
O state of matter
O conductivity
Answer:
the answer is D
Explanation:
hope it helps
"During a chemical reaction, you must have the same amount of substance
on both sides of the quation" This statement is the definition for the *
Answer:
This statement is the definition of law of conservation of mass.
Explanation:
Law of conservation of mass:
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by French chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
For example:
In given photosynthesis reaction:
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂
there are six carbon atoms, eighteen oxygen atoms and twelve hydrogen atoms on the both side of equation so this reaction followed the law of conservation of mass.
Let us consider the general chemical reaction.
A + B → C
5g + 5g 10g
Help pls:)?
If the low power objective has 10X printed on it, what would be the total magnification when looking through the microscope?
Answer:
The magnification of the microscope is equal to the magnification of the ocular lens times the magnification of the objective lens. Since the objective lens has 10x printed on them at "low power". The total magnification would be 10 times 10.
Explanation:
i hope this helps C:
What do most mineral on Earth's surface contain?
Answer:
Explanation:
shallow sea
A shallow sea is best choice, although both are evaporites and would most likely be formed as either the sea evaporated, or in a playa setting (dry lake bed in a desert)
Answer:
oxygen and silicon
Explanation:
https://courses.lumenlearning.com/earthscience/chapter/minerals-and-mineral-groups/
"Nearly all (98.5%) of Earth’s crust is made up of only eight elements – oxygen, silicon, aluminum, iron, calcium, sodium, potassium, and magnesium – and these are the elements that make up most minerals."
Of available answers:
a) nitrogen and oxygen
b) sulfur and hydrogen
c) silicon and nitrogen
d) oxygen and silicon
Only oxygen and silicon are both included on the list
What is the name for the type of graph shown in the image below?
Box-and-whisker
Histogram
Line
Scatter plot
Answer:
Scatter plot
Explanation:
Because the plot is scattered all over the place
If heat is required for a chemical reaction to occur, from where does the energy come?
Answer:
Chemical energy is energy stored in the bonds of chemical compounds, like atoms and molecules. This energy is released when a chemical reaction takes place. Usually, once chemical energy has been released from a substance, that substance is transformed into a completely new substance.
Explanation:
Add 92.2 km to 9426 m and report the answer in km. 92.2 km + 9426 m = ____ km
Answer:
Sum of both value is 101.63 km
Explanation:
Given data:
1st value = 92.2 km
2nd value = 9426 m
Sum of both value in km = ?
Solution:
We know that there are 1000 m in 1 km. Thus,
92.2 km + 9426 m/1000 m × 1 km = 101.63 km
Thus, sum of both value is 101.63 km
3.
What are valence electrons? How do you quickly determine the number of valence electrons an
atom has?
Answer:
Electrons that arent electrons
Explanation:
I teach chem
Answer:
Valence electrons are the electrons found in the highest and main energy level of the atom, being these responsible for the interaction between atoms of different species or between atoms of the same species. You can quickly determine these by looking at a periodic table like this one... Which is where the roman numbers come in and show the valence electrons. (THIS TABLE IS IN SPANISH, I hope you still recognize the symbols.) :))
how are compounds with metallic bonds similar to ionic compounds?
Answer:
Metals do not form double and triple bonds in general because metals want to lose electrons, not share, in order to become stable, and both compounds have high melting ppints
Compounds with metallic bonds and ionic compounds are similar in their melting point and boiling point, conductivity, solubility in polar solvents etc.
Ionic compounds are chemical compounds that are formed by the electrostatic attraction between oppositely charged ions.
Compounds with metallic bonds and ionic compounds are similar in several ways. Some of the similarities are:
1. High melting and boiling points: Both metallic and ionic compounds have high melting and boiling points due to the strong forces that hold the atoms or ions together.
2. Conductivity: Both metallic and ionic compounds are good conductors of electricity due to the presence of charged particles that can move freely.
3. Brittle: Ionic and metallic compounds are generally brittle in nature, meaning that they are prone to breaking or shattering when subjected to stress.
4. Solubility in polar solvents: Both metallic and ionic compounds are generally soluble in polar solvents such as water, due to the polar nature of the molecules.
In conclusion, compounds with metallic bonds and ionic compounds share several similarities. Both have high melting and boiling points, are good conductors of electricity, are brittle, and are generally soluble in polar solvents.
Learn more about ionic compounds here:
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