Which of the following is a pure substance?
Chlorine B. salt solution C. bronze D. salad dressing
What is the boiling point of pure water?
About 1000 C B. exactly 1000 C C. it varies D. slightly above 1000 C
Which is an example of a chemical change?
Water evaporating B. butter melting C. match burning D. powder being made
Which of these indicate a chemical change?
Color change B. temperature change C. gas-forming D. all of the above
Which of these is an impure substance?
Tap water B. gold C. carbon dioxide D. boron
Answer:
1. B
2. 100 C
3. C
4. D
5. D
Explanation:
if the velocity of an object is doubled, its kinetic energy is multiplied by
Can someone help me? It needs to have a diagram that has arrows.
Answer: The enthalpy change for formation of butane is -125 kJ/mol
Explanation:
The balanced chemical reaction is,
[tex]C_4H_{10}(g)+\frac{13}{2}O_2(g)\rightarrow 4CO_2(g)+5H_2O(l)[/tex]
The expression for enthalpy change is,
[tex]\Delta H=[n\times H_f{products}]-[n\times H_f{reactants}][/tex]
Putting the values we get :
[tex]\Delta H=[4\times H_f_{CO_2}+5\times H_f_{H_2O}]-[1\times H_f_{C_4H_{10}}+\frac{13}{2}\times H_f_{O_2}][/tex]
[tex]-2877=[(4\times -393)+(5\times -286)]-[1\times H_f_{C_4H_{10}}+\frac{13}{2}\times 0][/tex]
[tex]H_f_{C_4H_{10}=-125kJ/mol[/tex]
Thus enthalpy change for formation of butane is -125 kJ/mol
what is the smallest halogen atom
Answer:
Hey mate...
Explanation:
This is ur answer.....
This is because fluorine atoms are the smallest of the halogens—the atoms are bonded close together, which leads to repulsion between free electrons in the two fluorine atoms.
Hope it helps you,
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Does axons have insulation
Answer: Yes they do;
Explanation:
Axons, the long projections of neural cells that make up our peripheral nervous system's nerves, are comparable to power wires in that they have dense electrical insulation and can easily transmit impulses from the body and signals from the brain to a toe, for example.
Suppose a fox population exists in an ecosystem. Some of the foxes maintain a heavy coat year-round, while others shed their heavy coat in the summer. Summers in this ecosystem
are becoming steadily hotter because of global warming. Which members of the species will most likely be able to adapt to the changing temperatures?
subject science
Answer:
The fox who shed their heavy coat in the summer.
Explanation:
If a fox has the ability to shed its coat in the summer, it will have no difficulties adapting to new temperatures even during winter. However, the heavy-coated one will.
How many moles of NaCl are contained in 100.0 mL of a 0.20 M solution?
Answer:
0.02 mol.
Explanation:
How many moles of H2O form when 4.5 moles O2 reacts?
Explanation:
Start with a balanced equation.
2H2 + O2 → 2H2O
Assuming that H2 is in excess, multiply the given moles H2O by the mole ratio between O2 and H2O in the balanced equation so that moles H2O cancel.
5 mol H2O × (1 mol O2/2 mol H2O) = 2.5 mol O2
Answer: 2.5 mol O2 are needed to make 5 mol H2O, assuming H2 is in excess.
List four functions that different proteins have in living organisms.
Answer:
Proteins have different functions within living beings: Cellular transport. Structure of hair, muscle, nails, cell components and cell membranes. Biological catalysts or enzymes.
Explanation:
I hope this answer has helped you
Answer:
Enzymes and antibodiesCan someone pls help me with a paragraph of what endangered wildlife means ?
Answer:
Endangered wildlife means that something is at risk of extinction.
Explanation:
Hope I helped
The structure of the Earth is divided into four major components: the crust, the mantle, the outer core, and the inner core.
A. True
B. False
Name the 6 kinetic factors
What does it mean when a cell is multicellular?
options:
A.) Multicellular organisms are simple. They contain cytoplasm, ribosomes, DNA and a cell membrane
B.) Multicellular organisms are made of many cells and have specialized shapes that allow them to perform specific functions
C.) Multicellular organisms are made of one cell and have simple shapes that allow them to perform multiple functions
D.) Multicellular cells do not come from pre-existing cells.
Answer:
B.) Multicellular organisms are made of many cells and have specialized shapes that allow them to perform specific functions
Explanation:
Multicellular means that there is more than one cell.
Hope this helps!
What is the temperature range for our planet? Why is this important?
Answer:
are temperature range for are planet is -129 ⁰F (-18⁰C) that's the minimum.
+136⁰F (+58⁰C) this is the maximum surface temperature
Explanation:
"the planet is not too close or too far away from the sun, earth's atmosphere also plays a vital role is regulating the temperature by providing a blanket of gases that not only protects us from excessive heating and harmful radiation from the sun, but also traps heat rising from earth's interior core, keeping us warm"- Space.com
What is the mass of propane, C3H8, in a 27.5 L container of gas at STP?
Answer:
54 g
Explanation:
STP means 22.4L/mol
27.5/22.4=1.23(mol)
1.23 mol of C3H8=1.23*44= 54 g
what is a food web made up of
Answer:
A food web is made up of all the food chains in a single ecosystem. Each living thing in an ecosystem belongs to many food chains. A food chain is a path that energy takes through a certain ecosystem. Trophic Levels. Organisms in food webs are grouped into categories called trophic levels.
Explanation:
I HOPE THIS HEPLS HAVE A WONDERFUL DAY!:)
Answer:
you didnt say if it was an animal or people food web so imma just try my best to explane tis is an animal food web. So it really is just showing was the animals eat and if they eat other animal basicly.
Explanation:
A pine tree seed was produced by self-pollination. How many parents does this seed have?
A. one
B. two
The pine tree that produced the seed would be the only parent of a pine seed that was formed through self-pollination. So, the correct option is A.
What is Self-pollination?In the process of self-pollination, pollen from one flower or plant fertilizes the egg cells of another flower or plant. For self-fertilization to occur, both male and female reproductive components must be present within the same flower or plant.
The pollen from the male flower component, the anther, is carried to the female component, the stigma, during self-pollination either by the wind or by pollinators like bees, butterflies, or birds.
A pine tree that produces seeds will be the sole parent of pine seeds that form through self-pollination. Self-pollination occurs when pollen from the same pine tree fertilizes the pine tree's own egg cells, producing seeds with the genetic makeup of only one individual.
Therefore, the correct option is A.
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which type of window is double glazed window
Answer:
Hope this helps and have a good day!
Explanation:
Double glazed is a fancy term for a window that has two panes of glass. There are also triple glazed windows (three panes). The multiple panes of glass in a single window frame helps with insulation.
Q
1 At which electrode does reduction always take place?
2 Give the half-equation for the reaction at the anode, during
the electrolysis of these molten compounds:
a potassium chloride b calcium oxide
3 Give the two half-equations for the electrolysis of:
a a concentrated solution of hydrochloric acid, HCl
b a dilute solution of sodium nitrate, NaNO3
c a dilute solution of copper(II) chloride, CuCl2
i’m not sure if this is even the right subject lol but anyways
List 4 interesting facts about the element Cobalt
Answer:
Cobalt was the first metal to be discovered since prehistoric times and the first metal with a recorded discoverer.
Cobalt-60 is used to create gamma rays which are used to treat cancer and to sterilize medical supplies.
Cobalt is one of only three naturally occurring magnetic metals, making it very useful for the uniquely calibrated magnets found in generators and hard drives. ...
Cobalt has been utilized by man for at least the last 2,600 years, providing blue pigments for glassware and ceramics.
Explanation:
Answer:
- Doesn’t exist naturally on earth.
- Isolated in 18th century
- we use cobalt for magnets
- isn’t rare
Which element is more reactive? *
Cs
Rb
Answer:
Rubidium is a typical but very reactive member of the series of alkali metals. It is appreciably more reactive than potassium, but less so than caesium, and so would be expected to react more violently with those materials that are hazardous with potassium or sodium.
Answer:
Rb is more reactive .
Rubidium is the second most reactive metal and is very soft, with a silvery-white lustre.
..................
What rule/principle states that electrons in the same sublevel (p, d, or f) are placed in individual orbitals, before they are paired up, to increase atomic stability?
Aufbau principle
Hund’s rule
Pauli exclusion principle
Answer:
Hunds Rule
Explanation:
The principle states that electrons in the same sublevel (p, d, or f) are placed in individual orbitals, before they are paired up, to increase atomic stability is Aufbau principle, therefore option (a) is correct.
What is Aufbau principle ?
Aufbau principle states that electrons are filled into atomic orbitals in the increasing order of orbital energy level.
According to the Aufbau principle, the available atomic orbitals with the lowest energy levels are occupied before those with higher energy levels.
The rule/principle states that electrons in the same sublevel (p, d, or f) are placed in individual orbitals, before they are paired up, to increase atomic stability is Aufbau principle, therefore option (a) is correct.
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What might be a possible outcome if you left a soda in a glass bottle in the freezer for a very long time?
A.
The gases in the soda will increase in volume as the soda transitions from liquid to solid. This will cause the bottle to explode.
B.
The gases in the soda will decrease in volume as the soda transitions from liquid to solid. This will cause the bottle to implode or collapse.
C.
H2O will decrease in volume when transitioning from a liquid to solid state. This will cause the bottle to implode or collapse.
D.
H2O will increase in volume when transitioning from a liquid to solid state. This will cause the bottle to explode.
A the soda will increase in volume
DONT SKIP OR ELSE what solids, liquids, and gases does the human body produce
farting pooping peeing :3
Balance this chemical equation. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the coefficient is "1."
Choose... H 2 O 2 → Choose... H 2 O + Choose... O 2
Which solution will conduct electric current a sugar solution or a salt solution
Which sets of elements have similar chemical and physical properties?
1. Mg and Ra 2. Al and P 3. Be and Ba 4. Na and Cl
1 & 2 ,
2 & 3
1 & 3
2 & 4
Answer:
1 & 3
Explanation:
Elements have similar chemical and physical properties if and only if they belong to the same group of elements in the periodic table.
A group of elements in the periodic table is a family of elements, the elements in the in the same group have the same number of valence electrons in their outermost shell, share similar chemical reactivity (with slight variation within the group) and similar physical properties (with slight variation within the group).
Magnesium, radium, beryllium and barium all belong to group 2 hence they have similar chemical and physical properties.
I need help finding the volume, can't tell if i'm over thinking or if i'm wrong ;(
64.26,162.30,98.04,0.0983 if you cant read my handwriting
Answer:
98.04 ml
Explanation:
density of water is 1g/ml
since volume =mass/density
=98.04/1
= 98.04
help..................
Answer:
Volcanic eruption
Explanation:
a crater is this bowl shaped hole in the ground, and it is caused by a meteorite or volcanic activity
Convert the following temperature units (Hint: K = °C +273)
A) 50°C = __________ K
B) 288 K = __________°C
Answer: a- 323 b- 15
Explanation: