Answer:
1.a 2.d 3.c 4.b
Explanation:
Answer:
18.B
19.B
20.D
21.A
Explanation:
What was the time frame?
500 Million Years Ago
900 Million Years Ago
650 Million Years Ago
4.6 to 4 Billion Years Ago
Answer:
If you are referring to the Precambrian time, the answer is 500 Million Years Ago.
Explanation:
Precambrian time is the time period that started with the formation of Earth and ended about 500 million years ago.
why do astronomers use frequencies other than the visible ones when they are investigating the universe?
Which of the following is a unit for acceleration?
A) m/s
B) m/s2
C) s/m 2
D) s/m
Which of the following would be true when iodine gains valence electrons?
A. it would form a cation with a -1 charge.
B. it would form a cation with a +1 charge.
C. it would form a anion with a -1 charge.
D. it would form a anion with a +1 charge.
Answer:
C. it would form a anion with a -1 charge.
Explanation:
The elements of group 17 are called halogens.
These are six elements Fluorine, Chlorine, Bromine, Iodine, Astatine. Halogens are very reactive these elements can not be found free in nature. Their boiling points also increases down the group which changes their physical states. i.e fluorine is gas while iodine is solid.
They require only one electron to complete the octet and get stable. Thus they form anion with charge -1 when they gain electron.
l + e⁻ → I⁻
They form ionic compound with alkali and alkaline earth metal such as sodium chloride (NaCl), Barium iodide (BaI₂) etc.
Properties of Iodine:
1. it is present in solid form.
2. it is crystalline in nature.
3. it is very corrosive and has pungent odor.
4. it can not react with oxygen and nitrogen.
What is the energy of a 3.12 x 10^18 s-1 wave?
A. 4.75 x 10 ^42 J
B. 5.74 x 10^-7 J
C. 2.07 x 10 ^15 J
D. 8.6 x 10 ^ 4 J
Among electromagnetic waves, UV rays are most dangerous because exposure to these radiation cause serious problems in living organism. The energy of wave is 2.08×10⁻¹⁵J.
What is electromagnetic wave?
Electromagnetic wave is a wave which contain two component one is electric component and other is magnetic component. The electric and magnetic component are perpendicular to each other. There are so many wave that comes under electromagnetic wave like infrared wave , radio wave .There is a relation between energy of wave. frequency of wave
Mathematically,
E=hv
where,
E = energy of electromagnetic wave
h is planks constant having value 6.67×10⁻³⁴js
v= frequency of wave
substituting the given values
E= 6.67×10⁻³⁴js×3.12 x 10¹⁸ s⁻¹
E= 2.08×10⁻¹⁵J
Therefore the energy of wave is 2.08×10⁻¹⁵J.
To know more about electromagnetic wave, here:
https://brainly.com/question/12289372
#SPJ2
The_____
is an organelle that can give instructions for a
cell to reproduce and send directions to organelles to make needed
materials.
Answer:
nnmnm
Explanation:
How many moles of titanium are there in 32.5 grams of titanium?
Answer:
0.159 moles of Ti
Explanation:
32.5 g of Ti x (1 mol of Ti / 204.4 g of Ti) = 0.159 moles of Ti
which cells carry nutrients from food to the rest of the cells in the body?
Answer: The circulatory system.
Explanation: The circulatory system, which is part of the "cardiovascular" system, is one of the eleven organ systems of the human body. Its main function is to transport nutrients to cells and wastes from cells (Figure 3.4. 1). This system consists of the heart, blood, and blood vessels.
The blood cells carry nutrients from food to the rest of the cells in the body.
What is the circulatory system?The human circulatory system moves important nutrients and minerals throughout the body and metabolic waste products out from the body. The human circulatory system contains blood, blood vessels, heart, and lymph.
The human circulatory system provides essential nutrients, minerals, oxygen, and hormones to different parts of the body and is responsible for collecting toxins from the cells and tissues to be purified or eliminated from the body.
The human circulatory system contains a wide network of blood vessels. These constitute arteries, veins, and capillaries. The primary function of blood vessels is to transport nutrients and oxygenated blood to all parts of the body.
The Circulatory system helps in sustaining all the organ systems and transports blood, nutrients, oxygen, and hormones throughout the body. It secures cells from pathogens and acts as an interface for cell to cell interaction.
Learn more about the Circulatory system, here:
https://brainly.com/question/10103458
#SPJ2
12
How many electrons shells would an atom of Sulfur have?Locate on your Periodic Table*
(5 Points)
03
6
16
O 32
13
1. How many moles are contained in 103.4g of sulfuric acid?
a) 2.9 * 10^22 molecules of sulfuric acid
b) 5.18 * 10^24 molecules of sulfuric acid
c)12.1 * 10^23 molecules of sulfuric acid
d) 6.35 * 10^23 molecules of sulfuric acid
Harry stores toxic chemical waste in a large steel tank that has only 15% of its volume underground. Jena lives in the wilderness and has her own gas pump connected to a 1,500-gallon tank of gasoline buried ten feet underground near her garage. Lars keeps three large tanks filled with formaldehyde and battery acid in his basement. Which of these people are covered by federal regulations regarding USTs?
Answer:
Only Harry and Jena
Explanation:
Under federal regulations, an UST is any one or a combination of tanks such that the volume of an accumulation of regulated substances is 10% or more beneath the surface of the ground.
Any UST system holding a mixture of hazardous waste and other regulated substances are also are not covered by federal regulations regarding USTs.
Farm or residential tank of capacity more than 11 gallons used for storing motor fuel is covered by federal regulations regarding USTs.
According to the given question,
Only Harry and Jena are covered by federal regulations regarding USTs.
What are the 3 ways that materials can bond?
Answer:
Ionic bonding
covalent bonding
metallic bonding
Answer:
Iether they Heat up and melt together, Gravity pulls them together into one, Or the atoms inside one decide to bond with the other.
Explanation:
Question 3 is weird but I ran out of answers.
An ionic bond occurs between a ___ and ___
Answer:
An ionic bond occurs between two opposite charges are attracted
Explanation: Two opposite charges are attracted to each other
A student measures the sides of a cube with a ruler and finds that the length of each side is 2.70 cm what is the volume of the cube in centimeter cubed
Answer
V= 19.68cm^3
Explanation:
V=a^3
a=2.70cm
V=2.70cm^3
2.70^3= 19.68
V=19.68cm^3
Answer:
V= 19.68 cm^3
Explanation:
V= a^3
V= 2.70cm^3
V= 19.68cm^3
I WILL GIVE YOU BRAINLIEST!!!
Refer to the Newsela article "How You Can Make a Solar Oven To Cook with a Pizza Box."
What is the author's purpose in mentioning variables in designing the solar oven?
to show how easy it is to produce solar energy
to encourage readers to vary the design
to explain how wasteful solar energy production can be
to show the author did not think too hard about the design
Answer:
Encourage readers to vary the design
Explanation:
What is the density of a 805 g sample of pure silicon with a volume of 2.3 cm3?
How do intrusive rocks form?
A. Lava cools slowly outside a volcano
B. Magma cools slowly inside a volcano
C. Molten material is cooled quickly by water
D. Magma is ejected into the air and cools slowly.
Which of the following represents a pair of isotopes?
A. Ca+2, Be+2
B. 12C, 14C
C. Fe+2, Fe+3
D. 7N, 8O
We have that
the Carbon isotopes represents a pair of isotopes
12C, 14COption B
From the question we are told
Which of the following represents a pair of isotopes?
A. Ca+2, Be+2 B. 12C, 14C C. Fe+2, Fe+3 D. 7N, 8OGenerally
Isotopes
This is defined as variant forms of an element with variant atomic mass but same proton number
Therefore
the Carbon isotopes represents a pair of isotopes
12C, 14C
For more information on this visit
https://brainly.com/question/17756498
A substance is found to have a volume of 50 mL in an open beaker. In a flask, it changes
shape but maintains a volume of 50 mL. This substance is most likely:
A-Liquid
B-solid
C-gas
Answer:
LIQUID
Explanation:
The substance found to change shape in a different container but maintained volume is most likely a liquid.
STATE OF MATTER:Matter is any substance that has weight and occupies space. Matter can exist in three different states namely:
SolidLiquidGaseousLiquid as a state of matter is characterized by weak bonds that holds its particles together, hence, liquids flow.
Liquids assume the shape of the container that holds them. Hence, according to this question, the substance found to change shape in a different container but maintained volume (50ml) is most likely a liquid.
Learn more about liquids at: https://brainly.com/question/9402776
explain how are you able to drink liquid through a straw
Answer:
the suction pulls out the air in the straw and the liquid comes up with the suction.
Answer:
ya that is correct
Explanation:
Which 2 energy transformations are shown in the photo? Please help!!
Answer:
The answer Is B. Chemical energy--> electromagnetic energy
Answer:
B. Chemical energy ---------> electromagnetic energy
D. Chemical energy ---------> thermal energy
Explanation:
I took the quiz
Convert 380 K to degrees F.
Answer:
224.33
Explanation:
Answer:
224.33
Explanation:
4. How does the water vapor change as altitude increases?
Answer:
it drifts through the atmosphere and the vapor absorbs heat then the warm air rises up therefore leaving the planet's surface and releasing the heat back into the upper part of the atmosphere
In the first propagation step of the bromination of 2,3-dimethylbutane, the newly formed Br radicals react with the molecules of 2,3-dimethylbutane. Give the major products formed by the first propagation step including both organic and inorganic products. Draw the molecule on the canvas by choosing buttons from the Tools (for bonds), Atoms, and Advanced Template toolbars. Include all free radicals by right-clicking on an atom on the canvas and then using the Atom properties to select the monovalent radical.
Answer:
See explanation
Explanation:
When the bromine free radical attacks 2,3-dimethylbutane, two free radicals may result. One of them is primary (formed by attack on then end -CH3 group) the other is secondary.
Recall that the order of stability of free radicals is tertiary > secondary > primary > methyl.
Hence the secondary free radical is more thermodynamically stable hence it is the major free radical formed in the first propagation step.
what are class C fire extinguishers used for
electron configuration for silicon
Answer:
1s2, 2s2, 2p6, 3s2, 3p2
Explanation:
see the guide on the given electron configuration examples
50.5 kilometers to feet
50.5 km to ft is 165682.4
Answer:
the other guy is right its 165682.415
What is cr2s3 bond type?
Answer:
ionic bond
Explanation:
because cr is a metal and s is non-metal
Lactic acid, C3H6O3, is a monoprotic acid that is available in solid form. Determine the concentration of an unknown solution of sodium hydroxide, in moles per litre, given that it takes 18.34 mL to neutralize a solution containing 0.821 g of lactic acid. Write a balanced chemical equation for the reaction .
Answer:
0.497 moles/L
Explanation:
The reaction that takes place is:
C₃H₆O₃ + NaOH → C₃H₅ONa + H₂OFirst we calculate the moles of lactic acid in 0,821 g, using its molar mass:
0,821 g ÷ 90 g/mol = 9,122x10⁻³mol lactic acidOne mole of lactic acid reacts with one mole of sodium hydroxide (it is a monoprotic acid), so in 18,34 mL of NaOH solution there are 9,122x10⁻³moles of NaOH:
18.34 mL ÷ 1000 = 0,01834 L 9,122x10⁻³mol ÷ 0,01834 L = 0.497 moles/LHelppp. Calcium reacts with bromine to form Calcium bromide
Ca - - - - > Ca+2
Br2 - - - - > 2br
A. Complete the equation by adding electrons
[tex]\mathfrak{\huge{\pink{\underline{\underline{AnSwEr:-}}}}}[/tex]
Actually Welcome to the Concept of the Chemical Bonding.
Since we know that, calcium shares 2 electrons and Bromide being a halogen accepts 1 electron at a time,
So 2 bromides combine together to form a bond with Calcium, so we get as,
Ca2+ + 2Br -----------------------> CaBr2
CaBr2 is the compound formed.