50 POINTS!!!
When writing a chemical reaction equation, what does the arrow ( ---> ) represent?
A. the reactants are making the products
B. the direction of the chemical equation
C. the chemical reaction cannot be reversed
D. all of the above
The condition or progress of a reaction is represented by reaction arrows. The chemical reaction arrow is a single straight arrow that points from the reactant(s) to the product(s) and by-products, as well as side products.
I think this should help you find the answer more easy!
Which best describes the purpose of a fever?
Answer:
when you have a fever your body is trying to fight off a virus or some other kind of bad Bacteria
Explanation:
I think this because everyone has at least had a fever when they were sick and when you are sick you are likely to have a fever because your body is fighting off a bad bacteria
NEED HELP ASAP 20 POINTS !!!!!What does a subscript in a chemical formula tell you? For example the 3 in Rb3PO4 the number of atoms of the element symbol it follows the number of atoms of the element symbol it is in front of the number of molecules
Answer:
The answer should be A
Explanation:
because the definition of a subscript is that they indicate the number of atoms of an element present in am molecule or formula unit.
Answer:
The first choice. The rule is go left. Those subscript numbers always talk about the element to the left of them.
Explanation:
The straight forward answer is the first one.
You should always answer that when reading the chemical make up of molecules. Let's look at some examples.
C8 H18
Consider the 8. It must be describing how many carbons there are. If it was meant for the hydrogen, then what does the 18 mean? You wouldn't know.
Now look at something a lot more complicated.
Mg3(PO4)2
Use the going left rule. That satisfies Mg doesn't it? There are 3 of them and 3 is correct.
The two at the end is also straightforward if you think about it. It must be telling you how many molecules are in the brackets. If that were not so, then you wouldn't be able to tell what it did. So there are 2 PO4
But you still have the 4 to deal with. Use the going left rule again. 4 must be telling you how many oxygens you have inside the brackets. There are 4 of them.
Pretend your friend was absent from class today...
Write what you would say if you had to explain how and why elements to
your friend.
Answer:
how and why elements what?? why they exist?? im gonna assume that's what you meant, so elements exist because we're all on earth and without elements, we don't have resources to live. the earth is made of elements and if there were none, we wouldn't even have a planet
Explanation:
^
an organism that lives in or on another organism and causes harm to is a
A. host
B. parasite
C. prey
D. producer
the answer is B. Parasite.
Which two processes of the water cycle absorb energy from the Sun?
A evaporation and precipitation B sublimation and evaporation C condensation and transpiration D precipitation and condensation
Answer: of Earth's atmosphere occurs as energy, primarily from the sun, causes liquid water to transform to another phase. As this occurs, liquid water absorbs energy, causing it to evaporate and form water vapor. The process of evaporation absorbs tremendous amounts of incoming solar energy.
Explanation:
what is the mass of 4 moles of almunium atom
Answer:
108 grams
Explanation:
¿Qué estudia la química orgánica?
Answer: el estudio de la síntesis, estructura, reactividad y propiedades del diverso grupo de compuestos químicos construidos principalmente de carbono
Explanation:Hope I helped:)
Which characteristics do stable ecosystems tend to have
Answer:
Ecosystems contain biotic or living, parts, as well as abiotic factors, or nonliving parts. Biotic factors include plants, animals, and other organisms. Abiotic factors include rocks, temperature, and humidity. Every factor in an ecosystem depends on every other factor, either directly or indirectly.
What is the molar mass of H2S?
0 518
65.15 g
17 g
78.16 g
34.1g
What element is this? Is it a neutral atom or ion?
20. Which of the following is the correct name for N205?
O nitrate oxide
O dinitrogen pentoxide
O nitrous oxide
O nitrogen dioxide
Answer:
B!
Explanation:
Di stnds for 2 (N2)
pent = 5 (05)
Where must the moon be in its orbit for the full moon phase to be visible?
A
exactly crossing Earth's orbit of the sun
B
on the side of Earth opposite the sun
C
between Earth and the sun
D
directly above one of Earth's poles
Answer:
A.EXACTLY CROSSING EARTH'S ORBIT OF THE SUNThe moon must be exactly crossing Earth's orbit of the sun for the full moon phase to be visible.
What is Full moon?This is a situation where the Sun and the Moon are aligned on opposite sides of Earth with a corresponding illumination from the Sun.
It also occurs when the moon crosses the Earth's orbit of the sun and is denoted as option A.
Read more about Full moon here https://brainly.com/question/649027
#SPJ2
The speed you read from your speedometer is your ____________________. *
average speed
direction
instantaneous speed
distance
Answer:
it is your instantaneous speed
Explanation:
What part of the stem transports water and nutrients to the rest of the plant?
A) root cells
B) bark
C) xylem
D) phloem
Answer:
C) xylem
Explanation:
Write the molecular formula of poly(glycine)
Answer:
C2H5NO2
Explanation:
Glycine | C2H5NO2 - PubChem.
weight of glycine= 75.07 g/mol
How does the atmospheric pressure at altitudes above sea level compare with atmospheric pressure at sea level?
A. The atmospheric pressure above sea level is higher.
B. The atmospheric pressure at sea level is higher.
c. The pressures are the same.
D. Differences in pressures cannot be determined.
Answer:
Option B
The atmospheric pressure at sea level is higher.
Explanation:
Atmospheric pressure can simply be understood as the weight of the air molecules in the atmosphere. The higher we go up into the atmosphere, the thinner the air becomes. This means that the air present at higher heights is not so much, and hence, the air is lighter. This is why most fighter jets and mountain climbers need oxygen tanks to breathe properly.
Due to the fact that the air is less dense (lighter) at higher altitudes, it also means that the atmospheric pressure at higher altitudes is less.
Therefore, the atmospheric pressure at the sea level is higher than the atmospheric pressure at altitudes above sea level
Answer:
B. The atmospheric pressure at sea level is higher.
Explanation:
Write in the correct coefficients for the balanced equation:
Na +
Cl2 →
NaCl
Answer:
Na+Cl2-----NaCl
Explanation:
it's the chemical formula of common salt.
Answer:
2Na + Cl2 → 2NaCl
Explanation:
Na + Cl2 → NaCl
We have two chlorines on the left but only one on the right so it needs to be balanced.
If we put a 2 in front of NaCl we now have 2 chlorines on both sides but now 2 sodiums on the left and one on the right
Add another 2 in front of Na to get the full balanced equation
2Na + Cl2 → 2NaCl
Pls help on test (no old answers OR files)
During a combustion reaction, 9.00 grams of oxygen reacted with 3.00 grams of CH4.
What is the amount of the leftover reactant?
0.74 grams of methane
0.89 grams of methane
1.22 grams of oxygen
1.45 grams of oxygen
Use the reaction below for the decomposition of sodium azide
to sodium metal and nitrogen gas.
2NaNg(s) + 2Na(s) + 3N2(g)
What volume of nitrogen at STP is generated by the decomposition of 130.0 g NaNz?
Answer: The volume of nitrogen gas at STP is 44.8 L.
Explanation:
The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation for it follows:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex] ...(1)
We are given:
Given mass of [tex]NaN_3[/tex] = 130.0 g
Molar mass of [tex]NaN_3[/tex] = 65.01 g/mol
Using equation 1:
[tex]Moles of NaN_3=\frac{130.0 g}{65.01g/mol}=2mol[/tex]
For the given chemical equation:
[tex]2NaN_3(s) \rightarrow 2Na(s) + 3N_2(g)[/tex]
By the stoichiometry of the reaction:
2 moles of [tex]NaN_3[/tex] produces 3 moles of nitrogen gas
At STP:
1 mole of a gas occupies 22.4 L of volume
So, 2 moles of nitrogen gas will occupy [tex]=\frac{22.4L}{1mol}\times 2mol=44.8L[/tex] of volume
Hence, the volume of nitrogen gas at STP is 44.8 L.
A car travels at 24km/hr to the north. Then it travels 24km/hr to the east. Which is true about the car's acceleration?
a
The car accelerated because it speed increased.
b
The car accelerated because it changed direction.
c
The car did not accelerate because its speed did not change.
d
Only the velocity changed, not the acceleration not the acceleration.
Answer:
D
Explanation:
How many mL of a 2.0 M CuCl2 solution are needed to make 500 mL of a 0.5 M solution?
Answer: There is 125 mL of a 2.0 M CuCl2 solution are needed to make 500 mL of a 0.5 M solution
Explanation:
Given: [tex]M_{1}[/tex] = 2.0 M, [tex]V_{1}[/tex] = ?
[tex]M_{2}[/tex] = 0.5 M, [tex]V_{2}[/tex] = 500 mL
Formula used to calculate the volume is as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}[/tex]
Substitute the values into above formula as follows.
[tex]M_{1}V_{1} = M_{2}V_{2}\\2.0 M \times V_{1} = 0.5 M \times 500 mL\\V_{1} = 125 mL[/tex]
Thus, we can conclude that there is 125 mL of a 2.0 M [tex]CuCl_{2}[/tex] solution are needed to make 500 mL of a 0.5 M solution.
if 300.0g of chlorine is reacted how much calcium hydroxide is needed to react with it
Answer:
334.7g of Calcium Hydroxide are needed
Explanation:
Based on the reaction:
2Ca(OH)2 + 2Cl2 → Ca(ClO)2 + CaCl2 + 2H2O
2 moles of chlorine react with 2 moles of calcium hydroxide.
To solve this question we must find the moles of chlorine in 300.0g. These moles = Moles of Ca(OH)2. With the moles of calcium hydroxide we can find its mass as follows:
Moles Cl₂ (Molar mass: 70.90g/mol)
300.0g Cl₂ * (1mol / 70.90g) = 4.2313 moles Cl₂ = Moles Ca(OH)₂
Mass Ca(OH)₂ (Molar mass: 74.093g/mol)
4.2313 moles Ca(OH)₂ * (74.093g / mol) =
334.7g of Calcium Hydroxide are neededWhich is an example of cooperation?
individual ants together make up an ants’ nest
when an organism is more successful at hunting than another
when an organism finds a new way to get itself water
when people get together to stop the killing of the hawks, skunks, and weasels
How many moles of NaOH are in a 50.0 g sample of NaOH?
Answer:
The answer should be, 0.01
Explanation:
0.01 = moles of NaOH
[tex] \huge\boxed{ \boxed{\boxed{ \boxed{\mathcal{Answer ࿐ }}}}}[/tex]
[tex] \mathrm{1 \: mole \: of \: NaOH = 40 \: g }[/tex]
[tex] \mathrm{1g = \dfrac{1}{40} \: moles \: of \: NaOH}[/tex]
[tex] \mathrm{50g = \dfrac{1}{40} \times 50}[/tex]
[tex] \mathrm{1.25 \: moles \: of \: \: NaOH}[/tex]
_____________________________
[tex]\mathrm{ \#TeeNForeveR}[/tex]
_Ch7H16+_O2=_CO2+_H2O balancing the equation
Answer:
0,11,7,8
Explanation: hope this helps!
How many units long is the circumference of a circle with diameter of 18 units?
Answer:
56.52 units
Explanation:
hope that helps :)
Which combinations of particles form ionic bonds/compounds?
Answer:
Iconic bond is formed by cation and anion. A compound is made when atoms of two or more elements bond in a chemical reaction.
Explanation:
Define trace gas in simple
More efficient plumbing reduces water pollution by _______. a. using more water b. using less water c. using cleaner water d. using dirty water Please select the best answer from the choices provided
Answer:
b. using less water
Explanation:
Pollution can be defined as the physical degradation or contamination of the environment through an emission of harmful, poisonous and toxic chemical substances.
In the United States of America, the agency which was established by US Congress and saddled with the responsibility of overseeing all aspects of pollution, environmental clean up, pesticide use, contamination, and hazardous waste spills is the Environmental Protection Agency (EPA). Also, EPA research solutions, policy development, and enforcement of regulations through the resource Conservation and Recovery Act.
In homes and offices, an effective and efficient design of pipes and other water-related facilities would go a long way to reduce water pollution because the water used are well managed and properly disposed into sinkholes.
Hence, more efficient plumbing reduces water pollution by using less water
Answer:
B
Explanation: