Answer:
The atomic mass number is 45.
Hope this helps
List two functions organ systems can perform
Answer:
nervous system- sends signals to the brain
respiratory system- sends oxygen to the body
In a solution, the substance that has been dissolved is called the...
Answer:
solute
Explanation:
The substance being dissolved is called a solute. The thing the solute is being dissolved in is called a solvent.
What is the number of moles of a gas inside a 2.7L airbag at a temperature of 421K and pressure of 6.2atm?
Answer:
.48 moles
Explanation
n=PV/RT
What are the main properties of any liquid? Explain how you can measure the volume of a liquid sample.
Answer:
Liquid has the following properties -
- Liquids are almost incompressible due to the fact that molecules do not have a lot of space between them so they can not be compressed.
- Liquids have a fixed volume but shape varies according to the container it is placed in. It changes the shape even the volume is the same.
- Liquids flow from higher to lower levels.
- Liquids have their boiling points above room temperature, under normal conditions.
Measure the volume of a liquid sample-
The volume of the liquid can find out by dividing the mass of the liquid by the density of the liquid. D = m/v. The density of water is 1 gram/cubic centimeter.
how are enthalpy and entropy related to chemical reactions? (in simple terms)
Answer: Enthalpy is the heat content of a system. The enthalpy change of a reaction is equivalent to the amount of energy lost or gained during the reaction. A reaction is favoured if the enthalpy of the system decreases over the reaction. Entropy refers to the measure of the level of disorder in a thermodynamic system.
Explanation: hi lol
PLEASE HELP DUE IN 41 MINUTES
Based on the information in the tables, which salt will produce the greatest change in temperature when dissolved in water at 20 c
Answer:
See Explanation Note ...
Explanation:
Depending on amount added, Anhydrous CaCl₂ when dissolved in water solvent can become hot enough to blister ones skin when touched. On the cold side, Ammonium Nitrate will cool an aqueous solution enough to generate condensate frost on the outside of a glass beaker. I'm sure there are more examples but these two came to mind.
Answer:
KOH
Explanation:
I took the test
А
B
с
21. Which picture shows an irregular galaxy?
A. Image A B. Image B C. Image C
D. None of the abc
22. Alhich picture shows a spiral galaxy?
What is the meaning of democracy
Answer:
a system of government by the whole population or all the eligible members of a state, typically through elected representatives. its like everyone has a choiceExplanation:
Answer:
Demorcay is:The form of government of the entire population or of all qualifying members of the state, generally by elected representatives:
Explanation:
Hi! I'm doing homework about covalent bonds in Chemistry and I am supposed to figure out which 3 are right and which 3 are wrong. I'm having a really hard time. Any help is appreciated!
Answer:1,5,4
Explanation:
A teacher performed a demonstration of a chemical reaction by stretching a ballon containing Sodium bicarbonate (baking soda) over the top of a flask containing acetic acid (vinegar). When the sodium bicarbonate was added to the acetic acids the ballon began to inflate shown I'm the figure.
What will the total mass of the flask, the ballon, and products be after the reaction?
A. Less than 100g, because some of the solid baking soda disappears
B. 100g, because all of the atoms of the reactants remain in the flask
C. Less than 100g, because the gas has less mass than the solids and liquids
D. 100g, because the volume of gas inside the balloon has increased
Explanation:
D. 100g, because the volume of gas inside the balloon has increased
In chemical reactions that occurs in closed systems, the amount of matter is conserved. The total mass of the system is conserved because the gas did not escape and the volume has increased,
Answer:
d
Explanation:
What are uses of metals??
Instructions:
1. Do not give the invalid answer.
2. I want full correct answer with full explanations.
Answer:
Different uses of Metals
Metals are usually very strong, most durable and highly resistant to everyday wear and tear. As such, they have been used since ancient times for a lot of things. And even today with advances in technology and a lot of other things the uses of metals have broadened greatly. Metals even play a key role in the economy. Let’s look at some important and popular metals uses.
In the Construction Industry
In electronics
In medicine
Machinery, Refractory and Automobiles
Decorative products
Other Uses
In the Construction Industry
Metals are the main component in the construction industry. Metals like iron, steel amongst others are the main materials used in construction of buildings and even homes.
In Electronics
Another important application of metals are in electronics. As metals are good conductors of electricity, they are used to making wires and parts for equipments and gadgets that function on electrical current. Popular examples include, TV, mobiles, fridge, iron, computers etc.
In medicine
If you are wondering how, well from a biological perspective metals are found as micro-elements in our bodies. Besides, the presence of metal elements is crucial for several functions like transmission of nerve impulses, oxygen flow, reaction between enzymes etc. Some medicines are therefore liaised with metal compounds to treat certain deficiencies or sickness. Metals like, iron, calcium, magnesium, potassium titanium, and aluminum are used commonly in medicine in the form of antacids.
Apart from this, most of the equipments and tools used are made from metals.
Machinery, Refractory and Automobiles
This is one of the most common use of metals. They are used extensively in manufacturing machines for industries, agriculture or farming and automobiles which include road vehicles, railways, airplanes, rockets etc. Here, the commonly used metals are iron, aluminum and steel.
Besides these, most of the utensils that is used in the kitchen are made from metals like steel, aluminum, and copper. Due to a high temperature withstanding nature metals are preferred the most.
Decorative products
Metals such as platinum, gold, and silver come under the category of precious metals and have high economical value. These metals are widely used in making jewellery sets or for some decorative piece.
Other Uses of Metals
Some other uses and applications of metals are, they play an important role in security as the metals are used in making locks, strong safe, doors etc. Apart from this, furnitures are made from metal these days. Metals also find their uses in the military where they are used to manufacturing weapons and ammunitions. Some metals are used in galvanizing to protect from rusting.
These are some popular uses of metal. To know more about metals, different types, properties of metals and more you can keep visiting BYJU’S or you can also download our app for interesting content and learning experience
hey guys, i found this marble outside and covered in grease. so i took it in to wash it. can you please tell me what it is made of...plz
Answer:
it's probably just a ball of metal
Explanation:
maybe a metal marble.
Why a hot cup if water has more thermal energy than a cold cup of water?
Answer:
The hotter the substance, the more its molecules vibrate, and therefore the higher thermal energy
:)
Answer: Hot water has more thermal energy because the particles are farther apart thus they are moving faster. As particles move faster their thermal energy increases.
Explanation: Look in answer
How many moles are in 25 grams of nitrogen trihydride?
Explanation:
molecules NH3 = 1.47 moles x 6.02x1023 molecules/mole = 8.9x1023 molecules of NH3 (to 2 sig. figs.)
Consider the following reaction:
2 C2H6(g) + 7 O2(g) → 4 CO2(g) + 6 H2O(g)
At STP, what is the total volume of CO2 formed when 6.0 liters of C2H6 are combusted?
4 L
24 L
12 L
6 L
Answer:
4L
Explanation:
The first thing to do here is make sure that you have a balanced chemical equation. The equation given to you is actually unbalanced, so focus on writing a balanced version
2
C
2
H
6(g]
+
7
O
2(g]
→
4
CO
2(g]
+
6
H
2
O
(g]
Now, the problem provides you with a mass of ethane,
C
2
H
6
, and asks for the volume of carbon dioxide,
CO
2
, formed by the reaction at STP, Standard Temperature and Pressure.
As you know, STP conditions are defined as a temperature of
0
∘
C
and a pressure of
100 kPa
. Under these specific conditions, one mole of any ideal gas occupies exactly
22.7 L
- this is known as the molar volume of a gas at STP.
So, what this means is that if you know how many moles of carbon dioxide are produced by the reaction, you can use the molar volume of the gas to find the requested volume.
Use the molar mass of ethane to determine how many moles you'd get in that
240.0-g
sample
240.0
g
⋅
1 mole C
2
H
6
30.07
g
=
7.9814 moles C
2
H
6
Now, notice that you have a
2
:
4
mole ratio between ethane and carbon dioxide. Since ethane reacts with excess oxygen, you can assume that all the moles will take part in the reaction.
This means that the reaction will produce
7.9814
moles C
2
H
6
⋅
4
moles CO
2
2
moles C
2
H
6
=
15.9628 moles CO
2
So, if one mole of any ideal gas occupies
22.7 L
at STP, this many moles will occupy
15.9628
moles CO
2
⋅
22.7 L
1
mole CO
2
=
362.4 L
The answer is rounded to four sig figs, the number of sig figs you have for the mass of ethane.
During a lab activity, students were given samples of four different unknown elements. The students record their observations as shown in the table.
Sample 1 Sample 2 Sample 3 Sample 4
shiny shiny reddish-brown colorless
high electrical
conductivity
low electrical
conductivity
low electrical
conductivity
low electrical
conductivity
solid at room temp. solid at room temp liquid at room temp. gas at room temp.
flattens when hit
with a hammer
breaks into pieces when hit with a hammer
splashes when hit
with a hammer
no effect when hit
with a hammer
boiling point:
882.9 °C
boiling point:
3265 °C
boiling point:
58.8 °C
boiling point:
-268.9 °C
Which of the following BEST identifies which element(s) in the table are metallic?
A.
Sample 1, because it is shiny and a good conductor of electricity
B.
Samples 1 and 2, because both samples are shiny and solid at room temperature
C.
Sample 2, because it is shiny and solid at room temperature
D.
Sample 3, because it is the only sample that is a liquid at room temperature
Answer: D
Explanation: Metals are solid at room temp and also are shiny and can be flattened or broken into pieces when hammered and some metals are high and low conductors of electricity.
Metals have a characteristic property of conduction and malleability and thus sample 1 is metallic.
What is conduction?Conduction is defined as a process as a means of which heat is transferred from the hotter end of the body to it's cooler end.Heat flows spontaneously from a body which is hot to a body which is cold.
In the process of conduction,heat flow is within the body and through itself.In solids the conduction of heat is due to the vibrations and collisions of molecules while in liquids and gases it is due to the random motion of the molecules .
When conduction takes place, heat is usually transferred from one molecule to another as they are in direct contact with each other.There are 2 types of conduction:1) steady state conduction 2) transient conduction.According to the type of energy conduction is of three types:
1) heat conduction
2) electrical conduction
3)sound conduction
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What was the result of the atomic theory?
A. Alchemy was transformed into a true science.
B. The atom was discovered.
C. Scientists realized there were four main elements.
D. Chemists began to better understand the properties of matter.
The result of the atomic theory was that chemists began to better understand the properties of matter. Therefore, option (D) is correct.
The atomic theory, proposed by John Dalton in the early 19th century, postulated that matter is composed of indivisible particles called atoms. This theory revolutionized the field of chemistry by providing a framework to understand the behavior and interactions of different substances.
By recognizing that matter is composed of discrete atoms with specific properties, chemists were able to explain phenomena such as chemical reactions, the conservation of mass, and the formation of compounds. The atomic theory laid the foundation for modern chemistry, leading to advancements in understanding the structure of atoms, the development of the periodic table, and the ability to manipulate and engineer materials at the atomic level.
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The mass of an atom is equal to the number of
Neutrons, only
Protons, only
Neutrons plus protons
Electrons plus protons
Explanation:
proton number and neutron number sums up to form the mass number
Answer:
Neutrons & protons
Explanation:
hope it's help..
what went wrong with the key
Answer:
omoih
Explanation:
14. Energy (heat) is always transferred from ___ energy to ___ energy
A. low kinetic; high kinetic
B. high kinetic; high kinetic
C. high kinetic; low kinetic
D. low kinetic; low kinetic
Answer:i pretty sure it is high to low kinetic
Explanation: because heat or energy travels from hot heat to low heat which heat is the same as kinetic
What is in with those numbers? H2O?
Answer:
hydrogen atom and oxygen atom
are absolute temperature and kelvin temperature scale the same thing
Answer:
No they are not the same..
Explanation:
Absolute temperature is the temperature of an object on a scale where 0 is in the lowest possible energy state while the kelvin is a base unit of temperature.
What is meant by the term chemical bond? What subatomic particles(protons, neutrons, electrons) are most important in bonds?
Explanation:
Chemical Bonding refers to the formation of a chemical bond between two or more atoms, molecules, or ions to give rise to a chemical compound.
The subatomic particles that participate are electrons.
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20. What is the momentum of a 0.15-kilogram baseball moving at 20
m/sec?
1,5 kg*m/sec
3 kg*m/sec
O 15 kg*m/sec
O 30 kg*m/sec
What has to be equal during chemical equilibrium?
Select one:
a.The rate of forming products and the rate of reaction
b.The rate of the forward reaction and the rate of the reverse reaction
c.The rate of forming reactants and the rate of forming products
d.The rate of the forward reaction and the rate of forming reactants
Answer:
answer is B
Explanation:
please tell me if im incorrect, i'll fix it asap.
The rate of the forward reaction and the rate of the reverse reaction has to be equal during chemical equilibrium. Therefore, the correct option is option B.
When the forward and reverse reactions in a chemical reaction happen at the same rate, there is no net change over time in the concentrations of reactants and products. This is known as chemical equilibrium. The concentrations of the reactants and products are constant in this state, but the reaction is still ongoing for each species. The equilibrium constant (K), also referred to as the ratio of reactant to product concentrations, is constant at equilibrium. The temperature and the stoichiometry of the balanced chemical equation affect K's value.
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What is the charge of electrons?
Answer:
-1
Explanation:
Combustion analysis of a hydrocarbon produced
0.40g of CO2 and 0.205g of H20. Calculate the
empirical formula of the hydrocarbon.
HELP! A 25-mL solution of 2.0 M hydrobromic acid is kept in a bottle. How many moles of the acid is in the solution?
Answer: hello mason
Explanation: figure it out yourself