Answer:
a fossil
Explanation:
Answer:Fossil
Explanation:A remnant or trace of an organism of a past geologic age, such as a skeleton or leaf imprint, embedded, and preserved in the Earth's crust, usually in stratified rock.
what is the empirical formula 63.0 g Rb and 5.90 g O.
Answer:
Explanation:
1st convert given data into % per 100wt...
Total system mass = 63.0g + 5.90g = 68.9g
%Rb = 63.0g/68.9g x 100% = 91.4% per 100wt
%O = 5.9g / 68.9g x 100% = 8.6%
Then follow the following sequence of calculations...
% => grams => moles => mole ratio => reduce to smallest whole no ratio => empirical ratio => empirical formula
%Rb = 91.4% => 91.4g/ 85.5g·mol⁻¹ =>1.069mole
%O = 8.6% => 8.6g/16g·mol⁻¹ => 0.5375mole
Rb:O => 1.069 : 0.5375
Reduce by dividing by the smaller mole value
1.069/0.5375 : 0.5375/0.5375 => 2 : 1 <=> empirical ratio
∴ Empirical Formula => Rb₂O
After what part of the cell cyle does the cell begin interphase?
A.anaphase
B.prophase
C.cytokinesis
Explanation:
The prefix inter- means between, reflecting that interphase takes place between one mitotic (M) phase and the next. Image of the cell cycle. Interphase is composed of the G1 phase (cell growth), followed by the S phase (DNA synthesis), followed by the G2 phase (cell growth).
How many grams of C3H8 are in a 7 L tank at 293 K and 5.45 atm?
which atom has the smallest radius? Sr or I
Answer: Strontium has 219 pm
Iodine has 115 pm
Explanation: So the answer is Sr-Strontium
Thomas calculates the volume of an object by multiplying the measurements 1.74 cm x 2.3 cm x 3.09 cm. Using significant figures, how should the answer be reported?
Answer:
12 cm³
Explanation:
Always round to the place of the number with the least amount of significant figures.
1.74 and 3.09 have three significant figures. 2.3 has two significant figures. Therefore, the answer will be rounded to two significant figures.
1.74 cm × 2.3 cm × 3.09 cm = 12.36618 -> 12 cm³
(The 3 in the tenths place is less than 5 so drop it and all the numbers to the right of it.)
Hope that helps.
If 11 grams of a gas occupies 5.6 liters at STP, what is its gram molecular mass?
The molecular mass of gas = 44 g/mol
Further explanationGiven
5.6 Liters of gas
11 gram of gas
Required
The molecular mass
Solution
STP = Standart Temperature and Pressure , 1 atm 273 K
At STP , 1 mol gas = 22.4 L
So mol of 5.6 Liters gas :
= 5.6 : 22.4
= 0.25 moles
The molecular mass of gas :
= mass : mol
= 11 g : 0.25 moles
= 44 g/mol
What are the reactants in the reaction? What are their properties? Perform a quick Internet search, if needed.
The reactants in this reaction are sodium and chlorine. Sodium is a soft, silvery-white metal that is highly reactive. Chlorine is a poisonous greenish-yellow gas that has an odor and combines readily with other elements.
This might be the exact question so you might wanna rephrase it but good luck! :)))
A reactant is a substance that undergoes change during a chemical reaction.
A reaction in a chemical experiment is which takes place when there are mixtures between two or more reactants.
There are about four types of reactions which are:
SynthesisDecompositionSingle replacementDouble replacementPlease note that your question is not complete, therefore, i would give you a general overview to help you.
Some examples of reactants include:
HydrogenSodiumChlorine, etcRead more here:
https://brainly.com/question/12056938
How are sodium (Na) and potassium (K) similar?
A. They rarely react.
B. They are highly reactive.
C. They are hard metals.
D. They are soft nonmetals.
Answer:
B. They are highly reactive.
Explanation:
Answer:
B: They are highly reactive
Explanation:
Sodium(Na) and potassium(K) are in the same family/group which is the Alkali Metal group. These groups have their ability to displace H2(g) from water and create a basic solution. Alkali metals are also known to react violently and explosively with water. This is because enough heat is given off during the exothermic reaction to ignite the H2(g). Therefore, they are similar because of their reactivity.
Hope I helped!
Write a chemical equation of Dr. Jeff's demonstration using a battery to light steel wool on fire. The battery is used to allow a current to travel through the steel wool, thus heating it. Steel wood is made from iron (Fe).
Answer:
2Fe(s) + 3O2(g) --------> 2FeO3(s)
Explanation:
According to the question, a battery was used to light the steel wool by bringing the terminals very close together. When the battery came into contact with the steel wool, current was sent out through the thin wire. This caused the iron to heat up quite well.
Iron reacts with oxygen under these conditions as follows;
2Fe(s) + 3O2(g) --------> 2FeO3(s)
This is the chemical reaction that occurs when the steel wool is set on fire.
Chemical equation involved in Dr. Jeff's demonstration is
2 Fe+3 O₂[tex]\rightarrow[/tex]2 FeO₃
What is the effect of heating in chemical reactions?Battery is a device which helps in conduction of current. When a battery is used to pass a current through a substance in this case which is steel wool made up of iron it starts getting heated up.
The amount by which substance gets heated up is directly proportional to the current passing through it. As more current is passed through the battery it gets heated more.
During heating, the iron present in the steel wool reacts with oxygen to form iron oxide with iron present in the+3 oxidation state.When the heat exceeds a certain point the steel wool catches fire due to the heat generated. The heat causes the electrons present in steel wool of iron to move faster and collide with each other thus generating more heat.
Learn more about effect of heat in chemical reactions:
https://brainly.com/question/487518
#SPJ2
Which part of the mouth carries out each function? breaks down carbohydrates into sugars: cuts up food into smaller pieces:
Answer:
Saliva and teeth in this order
Explanation:
Make me BRANLIEST please
Large amounts of an unknown compound were isolated from seawater. The compound contained 32.0 grams ofbromine and 4.9 grams of magnesium. What is its percent composition?
Answer:
87% bromine and 13% magnesium
Explanation:
The compound contained 32.0 grams of bromine and 4.9 grams of magnesium.
We need to find its percent composition.
Mass of the sample = mass of bromine + mass of magnesium
= 32 g + 4.9 g
= 36.9 g
Percentage composition of bromine,
[tex]\%=\dfrac{32}{36.9}\times 100\\\\=86.7\\\\=87\%[/tex]
The percentage composition of magnesium,
[tex]\%=\dfrac{4.9}{36.9}\times 100\\\\=13.27\\\\=13\%[/tex]
So, its percent composition is 87% bromine and 13% magnesium.
I will give brainliest to whoever is first ❗️❕❗️❕❗️❕❗️
Which diagram best represents the reflection of the light from an irregular surface
But, an irregular surface, for every bump, the light bounces down up down up down up.
In conclusion, C is the best answer.
I hope this helped! +*♡
What kind of cell has a nonspontaneous voltage?
An electrolytic cell
A dry cell
A wet cell
A voltaic cell
Answer:
dry cell
Explanation:
because it stops when salt distribution becomes equal as bridge is not added
Answer:
a
Explanation:
a p e x :)
How many formula units are in 2.58 moles of Caci.?
Answer:
1.55 x 10²⁴ formula units
Explanation:
Given parameters:
Number of moles of CaCl₂ = 2.58moles
Unknown:
Formula units in the compound = ?
Solution:
To solve this problem, we must understand that;
1 mole of a substance contains 6.02 x 10²³ formula units
2.58 moles will contain 2.58 x 6.02 x 10²³ formula units
= 1.55 x 10²⁴ formula units
What state of matter has no visible shape and fills its container?
A: solid
B: liquid
C: has
Answer:
B
Explanation:
A 1,600-milliliter bucket of paint is at a temperature of 70°F. Then the paint is divided equally into four smaller buckets. Each bucket is at 70°F before the paint is poured.
the temperature of each 400 milliliter bucket is about _____ the temperature of the original bucket of paint.
a.the same as
b.four times
c.one fourth
science
Answer:
a.the same as
Explanation:
The temperature of each 400mL bucket is about the same as the temperature of the original bucket of paint.
This is because the temperature of the paint inside the bucket is not dependent on the amount of paint present.
In this regard, the temperature is an intensive property. So each of the boxes will have a temperature that is the same as that of the original bucket. Each of the particles have the same amount of kinetic energy.PLZ HELP !!!!!
Which statement correctly describes the main difference between body waves and surface waves?
Select one:
Surface waves are only longitudinal waves and body waves are only transverse waves.
Surface waves only travel across oceans and body waves travel across the Earth’s crust.
Surface waves are less damaging to man-made structures than body waves.
Surface waves travel across the Earth’s surface and body waves travel through the Earth’s interior.
Surface waves travel across the Earth’s surface and body waves travel through the Earth’s interior.
there you go :)
1. Which of the following is the amount of space that an object takes up?
1. density
2. volume
3. mass
Answer:
2. volume
Explanation:
Answer:
volume
Explanation:
Why do you think the different heating process result in different softness or hardness of the steel? Think about what steel is made of and how the atoms move .
Explanation:
Different heating process affect the microstructure of the steel in different ways. Thus, imparting different properties to the steel. For example, annealing is done is done to impart softness to steel, hardening is done to hardened the steel( eg: carburizing, nitriding, cyaniding) whereas tempering is done to improve the ductility of the steel.
Steel mainly contains iron and carbon. This percentage of carbon and iron decides the property of the steel. It is the % of carbon which is altered in different heating process that to obtained the desire microstructure in steel.
if the bending of rocks is to much what would happen? a. the rock will break
b. the rock will continue to fold
c. the rocks will be flattened
d. the rocks will build up an energy
Answer:
a, u cannot bend rocks
Explanation:
........yjmumtwjmyjy
How many moles are in 54 grams of C?
Will get brainliest.
Answer:
1.00 g
Explanation:
got it on pex
Which elements are found only along a zigzag line that divides columns 13 through 18 on the periodic table?
A. Metalloids
B. Metals
C. Nonmetals
D. Representative metals
Answer:
A. Metalloids.
Explanation:
Metalloids. Metalloids, also called semiconductors, are the elements that border the zigzag line on the periodic table.
What do the red arrows represent
Answer:
There are three forces acting on the skateboard. One of these forces is the weight of the rider. Another is the force of gravity on the board itself. The third is the force of the ground pushing up on the skateboard.
Lava that cools quickly forms: A. basalt B. granite C.quartz D. none the above
Answer:
I think the answer would be B. hope this helps!!
Explanation:
photosynthesis uses all of the following except __ to make food ?
how can paper that has already been used be physically changed
Answer:
the paper could be burn up
An analog and a digital version of an audio signal were copied.
Analog wave
Digital wave
Original
Original
wmin TAILLAMOUNTAIN
Varan TO
Copy
Copy
Which conclusion is supported by the results shown in the table?
A. Digital waves can be copied without damaging the audio signal,
whereas analog waves cannot
B. Both digital and analog waves become damaged during the
copying process
C. Analog waves can be copied without damaging the audio signal,
whereas digital waves cannot
D. Noise is introduced when both digital and analog waves are
copied
Answer:
The answer is A.Digital waves can be copied without damaging the audio signal, whereas analog waves cannot
Explanation:
I took AP EX quiz.
Which element has the largest atom (longest atomic radius) and which element has the smallest atom (shortest atomic radius)?
Answer:
Atomic radii vary in a predictable way across the periodic table. As can be seen in the figures below, the atomic radius increases from top to bottom in a group, and decreases from left to right across a period. Thus, helium is the smallest element, and francium is the largest.
Please dear lord help me I can’t solve it
