___________________________________________________________
Answer:
Chemical reactions that take place inside living things are called biochemical reactions. The sum of all the biochemical reactions in an organism is referred to as metabolism. Metabolism includes both exothermic (heat-releasing) chemical reactions and endothermic (heat-absorbing) chemical reactions.
___________________________________________________________
When hydrogen reacts with calcium metal, what are the oxidation numbers of the calcium and hydrogen in the CaH2 product?
Ca(s)+ H2(g) → CaH2
a. +2 and -1
b. +1 and -2
c. +2 and 2
d. 0 and 0
e. -2 and +1
Answer: e. -2 and +1
Explanation:
Oxidation number or oxidation state : It represent the number of electrons lost or gained by the atoms of an element in a compound.
Oxidation reaction is defined as the reaction in which a substance looses its electrons. The oxidation number of the substance increases.
Reduction reaction is defined as the reaction in which a substance gains electrons. The oxidation number of the substance gets reduced.
[tex]Ca(s)+H_2(g)\rightarrow CaH_2[/tex]
The oxidation number of calcium (Ca) in free state is 0 and in [tex]CaH_2[/tex] , it is -2.
The oxidation number of hydrogen in [tex]H_2[/tex] is zero and oxidation number of hydrogen in [tex]CaH_2[/tex] is +1 as in hydrides hydrogen loses electrons.
The oxidation number of calcium has been +2, and the oxidation number of hydrogen has been -1. Thus, the correct option is A.
The oxidation number can be defined as the number of electrons that have been lost by an atom in a chemical reaction.
The oxidation number can be calculated as the:
The oxidation number of Hydrogen when it combines with the less electronegative element has been -1.
There have been 2 atoms of Hydrogen that lose an electron, thus the total oxidation contribution of hydrogen has been -2.
The oxidation number of hydrogen has been -1.
The oxidation number of Calcium has been:
Ca atom has taken an electron from the hydrogen.
[tex]\rm Ca\;+\;e^-\;\rightarrow\;Ca^-[/tex]
The calcium takes one electron from each atom bonded. Thus the oxidation number of calcium has been +2.
The oxidation number of calcium has been +2, and the oxidation number of hydrogen has been -1. Thus, the correct option is A.
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if you start with 362 grams of C3 H8 how many grams of H2O will be produced
Answer:
52 g H2O (to 2 significant figures)
Explanation:
I hope you like my answer:)
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Which elements are diatomic?
1
H
3
Li
6
с
7
N
8
0
9
F
5
B
13
AI
2
He
10
Ne
18
Ar
15
P
16
S
17
CI
11
Na
19
K
4.
Be
12
Mg
20
Ca
38
Sr
31
Ga
33
As
35
Br
36
Kr
34
Se
52
Te
14
Si
32
Ge
50
Sn
82
Pb
114
FI
51
Sb
53
1
37
Rb
55
Cs
54
Xe
E
86
49
In
81
TI
113
Nh
56
Ba
83
Ві
84
Po
85
At
Rn
87
Fr
88
Ra
115
Mc
116
Lv
118
117
Ts
Og
Diatomic elements have to atoms of the element in a molecule.
What are diatomic elements?Diatomic elements are those elements whose atoms combine together to form molecules of the element. The elements that are diatomic in the list are;
HNOFClBrSeTeHence, diatomic elements have to atoms of the element in a molecule.
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The pH scale for acids and bases ranges from
A. 17
B. 0-14
C. 1-14
D. 1-12
Answer: 0-14
Explanation: Hope this helps
24. H.SO, has
a) Ionic bond
b) both lonic and covalent bonds
c) ionic covalent and coordinate bonds
d) covalent bond
Answer:
b
Explanation:
Both ionic and covalent bonds when it has dissolved into water it will become ionic compound but when it was in gas situation it was covalent compound.
Silver nitride is formed when a silver cation that has a 1+ charge combines with a nitrogen anion that has a 3- charge. Write the formula for the compound silver nitride.
A scientist added bacteria and a nutrient medium that could support the growth of the bacteria to a sterilized petri dish. No other materials were added. The graph models the growth of the bacteria over time.
Answer:
A scientist added bacteria and a nutrient medium that could support the growth of the bacteria to a sterilized petri dish. No other materials were added. The graph models growth of the bacteria over time. ... The bacteria did not reproduce in the system, and eventually each individual died at the end of its life cycle.
Explanation:
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The heat of fusion of a compound is 126 Joules
per gram. What is the total number of Joules of
heat that must be absorbed by a 15.0-gram
sample to change the compound from solid to
liquid at its melting point?
Answer:
1.89 × 10³ J
Explanation:
Step 1: Given data
Heat of fusion (ΔH°fus): 126 J/gMass of the sample (m): 15.0 gStep 2: Calculate the heat (Q) required to melt the sample
The fusion is the phase change from solid to liquid. We can calculate the heat required for the fusion of the sample using the following expression.
Q = ΔH°fus × m
Q = 126 J/g × 15.0 g
Q = 1.89 × 10³ J
How many Joules of heat will be given off by 55.0g of water as it cools from 87.3°C to 25.0°C?
Answer:
Q = -14322.77 J
Explanation:
Given data:
Mass of water = 55.0 g
Initial temperature = 87.3°C
Final temperature = 25.0 °C
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.°C
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
ΔT = 25.0 °C - 87.3°C
ΔT = - 62.3 °C
Q = 55.0 g×4.18 J/g.°C × - 62.3 °C
Q = -14322.77 J
Please answer!!! Will give brainliest to best answer!!
1. What is the difference between magma and lava?
2. Under what circumstances do large crystals form from a cooling magma?
3. Under what circumstances do small crystals form from a cooling magma?
4. What happens to the mineral particles in salt water when the water evaporates?
5. Explain how halite forms.
6. Explain how mineral veins form.
Answer:
I can answer 1, lqva is magma outside of the volcano
The answer to the problem: (2.1x103) x (4x105) = _____, written to the correct number of significant digits and in scientific notation is:
!! Carat denotes to the power. Example: 10^4 is 104 !!
Answer: The answer is [tex]8.4\times 10^8[/tex]
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
Thus for product of [tex](2.1\times 10^3)\times (4\times 10^5)[/tex]
In this problem, 2.1has 2 significant figures and 4 is an exact number with infinite significant digits thus product will have the least number of significant figures which is 2. So, the answer will be in 2 significant figures.
Therefore, the answer is [tex]8.4\times 10^8[/tex]
A student walks 15 km in 3 hours. What is the student’s average speed?
A :45 km/h
B :5 km/h
12 : km/h
18 : km/h
Answer:
5 km/h
Explanation:
divide the hours to the distance
When a living organism is successful in meeting all its needs ,this is called
A.active transport
B.endocytosis
C.homeostasis
D.exocytosis
Answer:
homeostasis
Explanation:
source Wiki
In biology, homeostasis (or “health”) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life.
Element X has two known isotopes. If 83% of the sample weighs 76 amu and the remaining 17% weighs 73.6 amu, what is the atomic mass of element X
Answer:
The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope. (Atomic mass is also referred to as atomic weight, but the term "mass" is more accurate.)
What mass of carbon monoxide gas (CO) would occupy a volume of 4.30 L at STP? Explain how you got the answer.
Answer:
5.38 g of CO.
Explanation:
From the question given above, the following data were obtained:
Volume of CO = 4.3 L
Mass of CO =?
Next, we shall determine the number of mole of CO that occupied 4.3 L at STP. This can be obtained as follow:
Recall = 1 mole of any gas occupy 22.4 L at STP.
1 mole of CO occupied 22.4 L at STP.
Therefore, Xmol of CO will occupy 4.3 L at STP i.e
Xmol of CO = 4.3 / 22.4
Xmol of CO = 0.192 mole.
Thus, 0.192 mole of CO occupy 4.3 L at STP.
Finally, we shall determine the mass of CO as follow:
Mole of CO = 0.192 mole.
Molar mass of CO = 12 + 16 = 28 g/mol
Mass of CO =?
Mole = mass /Molar mass
0.192 = mass of CO / 28
Cross multiply
Mass of CO = 0.192 × 28
Mass of CO = 5.38 g.
Therefore, 5.38 g of CO occupied 4.3 L at STP.
Which of the following factors affect the rate of weathering in an area?
A.
climate
B.
topography
C.
rock composition
D.
all of the above
Answer:
D
Explanation:
pretty sure D
What happened to the celery if you put in food color water
Answer:
the celery would change colour!
Explanation:
When a mixture of rock pieces, salt and water is filtered, what will be found as the filtrate and what will be found as the residue
Answer:
Filtrate: Mixture of salt and water.
Residue: rock pieces
Answer:
Salt solution will be the filtrate
and the rock pieces will be the residue.
Explanation:
This is because salt is soluble in water and hence
it cannot be filtered out of water giving as a salt solution as the filtrate and since the rock pieces are not soluble in water they are left out and they become the residue.
How many moles are present in a 5.8 g sample of copper?
A. 11
B. 0.091
C. 0.91
D. 5.5 x 10^22
please i need this for my finals
Explanation:
Molar mass of Cu = 63.5g/mol
Moles of Cu
= 5.8g / (63.5g/mol) = 0.091mol (B)
The number of moles present in a 5.8 g sample of copper is equal to 0.0913 mol. Therefore, option B is correct.
What is a mole?A mole can be defined as an international scientific unit that is used to determine for given count of particles. The particles are commonly identical entities but they are individually distinct.
A mole of the substance can be used to evaluate a large number of atoms, molecules, or particular particles. The amount of material can be measured as chemical entities of a substance in a sample.
The number of units in 1 mole of a material is equal to 6.023×10²³ which is called Avogadro’s constant.
Given, the mass of the copper = 5.8 g
The mass of one mole of copper = 63.5 g
We can calculate moles as, n = Mass/molar mass
Then, the number of moles of copper = 5.8/63.5 = 0.0913 mol
Therefore, the number of moles of copper is 0.0913 mol.
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What os the formula for hexaboron tetrabromide
Answer:
B6Br4
Explanation:
Chemical formula gives a representation of the number of atoms that each element in a compound or molecule. In this question which is asking to give the formula of hexaboron tetrabromide, the hexa means 6 while the tetra means four.
Since the number of atoms of each element is written as a prefix before the main element, this means that the chemical formula of hexaboron tetrabromide will be B6Br4.
Photosynthesis makes (__________) and (____________) for an ecosystem.
Answer:
Oxygen and Sugar (Glucose).
Explanation:
Plants are autotrophs, which means they produce their own food. They use the process of photosynthesis to transform water, sunlight, and carbon dioxide into oxygen, and simple sugars that the plant uses as fuel.
What is the mass of 0.20 moles of Ga₂(SO₃)₃?
Answer:
75.924 g
Explanation:
To answer this question we first need to calculate the molar mass of Ga₂(SO₃)₃:
Molar Mass of Ga₂(SO₃)₃ = (Molar Mass of Ga)*2 + (Molar Mass of SO₃)*3
Molar Mass of SO₃ = Molar Mass of S + (Molar Mass of O)*3 = 80.06 g/molMolar Mass of Ga₂(SO₃)₃ = (69.72 g/mol)*2 + (80.06 g/mol) * 3
Molar Mass of Ga₂(SO₃)₃ = 379.62 g/molThen we convert 0.20 moles to grams, using the molar mass of Ga₂(SO₃)₃:
0.20 mol Ga₂(SO₃)₃ * 379.62 g/mol = 75.924 gMass of 0.20 moles of Ga₂(SO₃)₃ is 75.924 g
Number of moles:It is defined as the ratio of given mass over molar mass.
Given:
Number of moles= 0.20 moles
To find:
Mass=?
We need to calculate molar mass of Ga₂(SO₃)₃ first:
Molar Mass of Ga₂(SO₃)₃ = (Molar Mass of Ga)*2 + (Molar Mass of SO₃)*3
Molar Mass of SO₃ = Molar Mass of S + (Molar Mass of O)*3 = 80.06 g/mol
Molar Mass of Ga_2(SO_3)_3 = (69.72 g/mol)*2 + (80.06 g/mol) * 3
Molar Mass of Ga₂(SO₃)₃ = 379.62 g/mol
Then we convert 0.20 moles to grams, using the molar mass of Ga₂(SO₃)₃:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} \\\\\text{Given mass}=\text{Number of moles}*\text{Molar mass}\\\\\text{Given mass}=0.20 moles*379.62 g/mol\\\\\text{Given mass}=75.92 grams\\[/tex]
Thus, the mass of 0.20 moles of Ga₂(SO₃)₃ is 75.92 grams.
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Perform the following
mathematical operation, and
report the answer to the
appropriate number of
significant figures.
15.673 + 14.752 + 8.4568 = [?]
Answer:
38.882
Explanation:
For all those Acellus kids XD
What is weathering?
A.
the process by which sediment is compacted into rock
B.
the process by which rocks are broken down into sediment
C.
the process by which sediment is transported from one place to another
D.
the process by which sediment is deposited and built up into landforms
Answer:
B.
the process by which rocks are broken down into sediment
The waste product of nuclear energy which is a possible pollutant is:
A.smoke
B.hot air
C.radiation
D.heat pollution to lake
Answer:
CCCCCCC
Explanation:
Answer:
C. radiation
Explanation:
the possible pollutant is radiation because nuclear energy causes ; electromagnetic waves are radio waves, light, infrared rays, UV rays, X rays, Gamma rays. These are well known and are used extensively in the fields of communications, industry, medicine and research.
Radiation is a term given for waves caused by electromagnetism and high energy particles .Radioactive substances have High energy particles which are tiny bits of matter that are made to move at high speeds releasing nuclear radiation. There are about 50 naturally occurring radioactive substances and More than 2000 man-made ones. There are three kinds of radioactive radiation – alpha particles, beta particles and gamma radiation.
How does wood produce chemical energy?
Wood absorbs oxygen to produce chemical energy.
Wood absorbs solar radiation to make chemical energy
Wood absorbs nitrogen gas to make chemical energy.
All living organisms produce unlimited amount of chemical energy.
Answer:
Wood absorbs solar radiation to make chemical energy.
The chemical energy of wood has been absorbed by solar radiation. Thus, option B is correct.
The wood has been the source of energy by the burning for a long duration. The chemical energy has been stored in the dry wood has been converted to light and heat energy on burning.
The energy stored in the wood has been comprised by photosynthesis, where the solar energy has been entrapped in the wood and is converted to chemical energy that is stored.
Thus, the chemical energy of wood has been absorbed by solar radiation. Thus, option B is correct.
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a.liver e.mouth i.stomach
b.colon f.pancreas
j.large intestine c.gallbladder
g.tongue k.villi d.esophagus
h.peristalsis l.teeth
_8. stores a substance called bile, which physically breaks down fat droplets
_9. Digestion begins when salivary gland secretions enter this
_10. Minute projection extending from the walls of the small intestine and involved in absorbing products of digestion
_11. used to cut, tear, and grind food; adult has 32
_12. when you swallow food, muscular movements carry the food along this structure
to the stomach
13. this organ absorbs excess water form undigested food prior to its release from
the body as a solid waste
_14. Muscular movement involving the walls of the digestive tract that serve to mix materials and move them along the tract
15. it pushes food to the back of the mouth prior to swallowing
_16. this organ produces bile and detoxifies a variety of substances
_17. produces digestive juices that are released into the small intestine
_18. another name for the large intestine
19. functions include mixing food and serving as a reservoir prior to the food being passed on to the small intestine
Answer:
8. c
9. e
10. k
11. L
12. d
13. j
14. h
15. g
16. a
17. F
18. b
19. i
Explanation:
The gallbladder stores a substance called bile, which physically breaks down fat droplets, hence the correct options are 8. C, 9. E, 10. K, 11. L, 12. D, 13. J, 14. H, 15. G, 16. A, 17. F, 18. B, 19. I.
What are the components of the digestive system?Digestion begins when salivary gland secretions enter the mouth. Teeth used to cut, tear, and grind food; adult has 32.
Villi are a minute projection extending from the walls of the small intestine and involved in absorbing products of digestion.
When you swallow food, muscular movements carry the food along the esophagus to the stomach. The large intestine absorbs excess water from undigested food prior to its release from the body as a solid waste.
Muscular movement known as peristalsis involving the walls of the digestive tract that serve to mix materials and move them along the tract.
Therefore, the correct options are 8. C, 9. E, 10. K, 11. L, 12. D, 13. J, 14. H, 15. G, 16. A, 17. F, 18. B, 19. I.
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_______ are white blood cells that recognize specific antigens, and ultimately destroy them.
O lymphocytes
O pathogens
O water
Answer:
Lymphocytes
Explanation:
Pathogens are particles that make you sick like bacteria, viruses, amoebas. Water is essential for life but that's for metabolism, not fighting off against infection or viruses.
Answer:
Lymphocytes
Explanation:
lymphocytes are a kind of white blood cell (WBC). Lymphocytes are cells of the immune system and help fight infection. Lymphocytes live in lymph nodes, but also in the bloodstream and all over the body. Lymphocytes come in two main types: B-cells and T-cells
Where as water is totally not white blood cells and pathogens are viruses and bacterium
Which of the following is a chemical property?
O volume
O flammability
O color
O weight
Answer:
your answer is flammability