Which of the following is the best definition of a chemical change?
A. All of these
B. The ability of something to undergo a change or reaction.
C. Something that can be observed or measured without changing the identity of the substance.
D. A change that alters the identity, or chemical composition, of a substance at the atomic level.
Answer:A
Explanation:
A scientist introduces an unknown type of particle into a cathode ray tube. The unknown particles travel in the same direction as the cathode ray. Which of the following statements is true?
A. The charge of the unknown particles is positive.
B. The charge of the unknown particles is negative.
C. The charge of the unknown particles is neutral.
Answer: B
Explanation:
What metal is highly reactive and bonds easily with other elements
Answer: alkali metal
Explanation: ONLY if that is in you suggestions
if not i think this is right
what if water didnt have a negative charge?
Answer:
Explanation:
It would be positively charge
What is water supply ?
Answer:
a water suppley is water that pepople buy to dreak and ues
Explanation:
How long does it take Earth to make one rotation on its axis?
12 hours
48 hours
24 hours
Please answer ASAP
Answer:
24 hours
Explanation:
There are 24 hours in a day cause that is how long for the earth to spin on its axis
Answer:
24 hours
Explanation:
The time it takes Earth to rotate so the sun appears in the same position in the sky, known as a solar day, is 24 hours. However, the time it takes Earth to complete one full rotation on its axis with respect to distant stars is actually 23 hours 56 minutes 4.091 seconds, known as a sidereal day.
Which of the following are directly proportional? *
volume and temperature
pressure and volume
pressure and temperature
If a laser operating at a wavelength of 488 nm and a power of 123.0 mW is turned on for 18.73 minutes, how many photons has it emitted?
Answer:
3.39e+20
Explanation:
We are the family members and love to
react with potassium (K).
Who we are?
Answer:wth does this even mean
Explanation:
A 10.0 cm sample of copper has a mass of 89.6 g. What is the density of copper?
Answer:
19.3 g/cm3
Explanation:
plz give branliest
What is the order of decreasing ionization energy?
1. cesium, barium, lead
2. barium, lead, cesium
3. lead, barium, cesium
4. barium, cesium, lead
5. lead, cesium, barium
6. cesium, lead, barium
Which scientist is credited with developing the fist scientific atomic theory
Answer:
German chemist G.E. Stahl
how does a phenol red-containing solution look if co2 level is low?
Answer:
The variables to be examined in relation to carbon dioxide use are the amount of light exposure and amount of dissolved CO2. Phenol red is yellow/orange under acidic conditions, that is when the pH of the solution is less than 7 (e.g. pH = 6). This occurs when the concentration of CO2 is high.
Explanation:
is this correct
A phenol red-containing solution with low CO2 level will appear red.
Phenol red is a substance that serves as an indicator. It changes in colouration in response to the acidity or alkalinity of solutions.
In acidic solutions, phenol red turns yellow while the colour is red in basic solution.
Solutions with high CO2 levels are acidic while those with little to no CO2 concentrations are basic.
Thus, in a low CO2 solution, phenol red will turn red and the solution will generally appear red.
More on acid/base indicators can be found here: https://brainly.com/question/16284171?referrer=searchResults
(WORD BANK - Neap, gravitational, greatest, moon, high, Spring, low, Sun)
Ocean tides are caused by the ______________ pull of the _______ and the _______. The moon has the __________ effect on the tides. When the Sun, moon and earth are in a straight line, we
have __________ tides. When the Sun, moon and earth are at right angles we have _________
tides. Spring tides are especially _________ tides while neap tides are especially _________tides.
Answer:
Ocean tides are caused by the gravitational pull of the moon and the sun. The moon has the greatest effect on the tides. When the Sun, moon, and earth are in a straight line, we have Neap tides. When the Sun, moon, and earth are at right angles we have spring tides. Spring tides are especially high tides while neap tides are especially low tides.
Explanation:
brainliest please. . . <3
Which of the following would not be made in a ribosome?
O enzymes
O cholesterol
O antibodies
O water-soluble hormones
Answer:
cholesterol(lipid)
Explanation:
Ribosomes are called PROTEIN FACTORY
Ribosomes are involved in protein synthesis
Any metabolite or substance protein in nature can be synthesized on ribosomes
enzymes are protein in natureantibodies are y shaped protective proteinswater soluble hormones are also amine or protein in natureSince they are protein in nature hence can be synthesized on ribosome.
WRONG OPTIONS:
CHOLESTEROL IS LIPID IN NATURE
LIPIDS ARE NOT proteins and cannot be SYNTHESIZED ON RIBOSOME
LIVER DOES THIS FUNTION OF CHLESTEROL SYNTHESIS.
standardization is the process of titrating a solution prepared from
Standardization is the process of titrating a solution that is prepared from: a carefully measured solid mass to accurately find the concentration of titrant.
What is titration?Titration is also known as volumetric analysis (titrimetry) and it can be defined as a chemical process in which a solution of known concentration (titrant) is carefully and slowly added to another solution of unknown concentration, so as to determine the concentration or quantity of the analyte.
Similarly, a process referred to as standardization is used to titrate a solution that is prepared from a carefully measured solid mass to accurately find the concentration of titrant.
Read more on titration here: brainly.com/question/24584140
at sea level, the average height of mercury in a barometer is
Answer: 760 mm
Explanation:
At sea level, a mercury column will rise a distance of 760 mm. At higher altitudes, the atmospheric pressure is decreased and so the column of mercury will not rise as high.
During the process of peer review, a scientific study must have:
Group of answer choices (( its not precision//validity ))
repetition
precision
accuracy
validity
Answer:
Accuracy
I guess
Cause then it makes sense
Hope this helps
How does a balanced chemical equation demonstrate the Law of Conservation of Mass? (1 point)
O it shows that only physical changes follow the Law of Conservation of Mass
O it shows that no atoms have been gained or lost during the reaction
O it shows that the properties of the elements stay the same after the reaction
O it shows that all compounds remain bonded after the reaction
Explanation:
A balanced equation demonstrates the conservation of mass by having the same number of each type of atom on both sides of the arrow. enjoy
Answer:
It show that no atoms have been gained or lost during reaction
Explanation:
Why is there gold on the inside of a cell phone but plastic on the outside
Answer:
Gold is chemically stable and conducts electricity.
Small pockets of gold are used to make mobile phone circuit board.
The plastic is lined to act as antenna gate. It's what makes a phone not a calculator but a communication point, since it allows the data flow, Bluetooth connection, Wi-Fi. Mainly, it allows radio waves to flow.
Science is based on the correspondence theory of truth, which claims that truth corresponds with facts and reality.
Answer:
true/ correct
Explanation:
It takes 40 mL of 0.10 M of hydrochloric acid (HCl) to neutralize 50 mL of sodium hydroxide (NaOH) for the following chemical reaction
HCl + NaOH → NaCl + H2O
The concentration of sodium hydroxide is _____.
0.125 M
0.08 M
0.10 M
0.04 M
Answer:
0.08 M
Explanation:
here...
1. water and a salt
2. Magnesium hydroxide reacts with HCl to produce a solution that is neutral.
3. titrant
4. 0.08 M
5. indicator
{quizlet: captncrun}
The concentration of sodium hydroxide is 0.08 M. The correct option is the second option 0.08 M
From the question,
We are to determine the concentration of sodium hydroxide
The given reaction is
HCl + NaOH → NaCl + H₂O
This means
1 mole of HCl is required to completely neutralize 1 mole of NaOH
To determine the concentration of sodium hydroxide,
We will use the formula
[tex]\frac{C_{A}V_{A} }{C_{B}V_{B}} = \frac{n_{A}}{n_{B}}[/tex]
Where
[tex]C_{A}[/tex] is the concentration of acid
[tex]C_{B}[/tex] is the concentration of base
[tex]V_{A}[/tex] is the volume of acid
[tex]V_{B}[/tex] is the volume of base
[tex]n_{A}[/tex] is the mole ratio of acid
[tex]n_{B}[/tex] is the mole ratio of base
From the give information
[tex]C_{A} = 0.10 \ M[/tex]
[tex]V_{A} = 40 \ mL[/tex]
[tex]V_{B} = 50 \ mL[/tex]
From the balanced chemical equation
[tex]n_{A} = 1[/tex]
[tex]n_{B} = 1[/tex]
Putting the above parameters into the formula, we get
[tex]\frac{0.10 \times 40}{C_{B} \times 50} = \frac{1}{1}[/tex]
Then
[tex]C_{B} \times 50 = 0.10 \times 40[/tex]
∴ [tex]C_{B}=\frac{0.1 \times 40}{50}[/tex]
[tex]C_{B}=\frac{4}{50}[/tex]
[tex]C_{B}=0.08[/tex]
Hence, the concentration of sodium hydroxide is 0.08 M. The correct option is the second option 0.08 M
Learn more here: https://brainly.com/question/14753195
I need help pleaseee
cân bằng phương trình Al + HCl → AlCl3 + H2
Answer:
Explanation:
Balance the reaction of Al + HCl = AlCl3 + H2 using this chemical equation balancer!
how should the mass of copper metal at the end of the reactions compare to the starting mass of copper?
Answer:
The produced mass of copper should equal the starting mass of copper.
Calculate the number of moles of NH3 formed by the reaction of 2 moles of N2 and 2 moles of H2,N2(g) + 3H2(g) forms 2NH3(g)
Answer:
we have to find the number of moles of NH₃ formed by reaction of 2 moles of N₂ and 2 moles of H₂. ... ∴ 2 moles of hydrogen will give = 1.33 moles of ammonia. therefore the no of moles of ammonia after the reaction would be 1.33 moles
the smallest unit of matter that retains the properties of that matter is
Answer:
here is your answer.
Explanation:
atom.
thanks for asking:)
Where in the cell do most aerobic respiration take place?
a)
mitochondria
b)
cell membrane
c)
nucleus
The reaction of C2H4 +Cl2 is what type of reaction.
Answer:
C2H4(g) + Cl2(g)→C2H4Cl2(g)
This is an example of synthesis reaction, when compounds are joined together.
When the skydiver is falling at a constant velocity after the parachute is open, what is their acceleration?
Answer:
Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward. ... The skydiver thus slows down. As the speed decreases, the amount of air resistance also decreases until once more the skydiver reaches a terminal velocity.
When the skydiver is falling at a constant velocity after the parachute is open, acceleration is zero.
The acceleration of the skydiver will be zero shortly after the parachute opens, but we can not call it as “acceleration due to gravity”.It's the acceleration due to gravity and air resistance together, and the forces cancel each other out to give an acceleration of zero.Once the parachute is opened, the air resistance overwhelms the downward force of gravity. The net force and the acceleration on the falling skydiver is upward.Learn more:
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