Which of the following changes is observed when we move across the row from left to right in the periodic table?
Atomic radius increases
Atomic radius decreases
Number of protons decreases
Chemical reactivity of metals increases
What is the name of a zinc and phosphorus mixture
Complete the sentence: Cellular respiration occurs ________________.
only in plant cells
only in animal cells
only in chlorophyll
in plant and animal cells
Answer:
in plant and animal cells
Answer:
In plant and animal cells
Explanation:
Which chemical(s) are reactants in the following chemical
equation?
C + O2 CO2
SELECT ALL THAT APPLY
а) C
b) 02
c) CO2
d ) There are no reactants in this chemical equation.
Answer:
A and B
Explanation:
The reactants in this chemical equation are C and O₂.
Given the chemical reaction is:
C + O₂ → CO₂
In a chemical reaction, reactants combines to give the product. The reactants are located to the left side of the expression.
The products are found on the right side .
A + B → C
reactants products
So, in the given reaction,
C and O₂ are the reactants and CO₂ is the product.
Answer: B and C
Explanation:
ur welcome
A student observes poor growth of plants in a garden containing high clay content. Clay content reduces drainage in soil. Which of these is the best method to improve plant growth in the garden?
A. water the plants once a month
B. add sand to the soil
C. mix soil with chemicals which absorb the air
D. do not dig or till the soil
Answer: Add sand to the soil
Explanation:
Just finished my test
Answer:
add more sand to the soil
Explanation:
What is the pressure in a 29.0-L cylinder filled with 45.5 g of oxygen gas at a temperature of 325 K ?
Answer:
P = 1.29 atm
Explanation:
Given data:
Volume of cylinder= 29.0 L
Mass of oxygen gas = 45.5 g
Temperature = 325 K
Pressure of gas = ?
Solution:
First of all we will calculate the number of moles of oxygen:
Number of moles = mass/molar mass
Number of moles = 45.5 g/ 32 g/mol
Number of moles = 1.4 mol
Pressure of oxygen:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
P ×29.0 L = 1.4 mol × 0.0821 atm.L/ mol.K × 325 K
P = 37.36 atm. L / 29.0 L
P = 1.29 atm
The chemical isoamyl acetate C7H14O2 gives the odor of pears. What is the percent oxygen in isoamyl acetate?
Answer:
[tex]\% O=24.6\%[/tex]
Explanation:
Hello!
In this case, since the by-mass percent of an element in a compound is computed by taking into account its atomic mass, the number of atoms in the molecules and the molar mass of the compound, we can write:
[tex]\% O=\frac{2*16.00}{130.18 } *100\%\\\\\% O=24.6\%[/tex]
Best regards!
How are you able to see cells?
Explanation:
you are to see cells By doing an experiment.
The number of particles in one mole of a chemical substances is 602,200,000,000,000,000,000,000 particles. What is the correct way to write this number in scientific notation?
6022 x 10¹⁹
0.6022 x 10²⁴
60.22 x x10²²
6.022 x 10²³
The correct way to write this number in scientific notation : 6.022 x 10²³
Further explanationScientific Notation is a standard form of writing numbers used in mathematical operations
The rules:
1. Writing order : first digit, decimal point, next digit
2. Then followed by powers of 10 (the value can be +/-)
If the value is> 10 (the power of 10 is +), the decimal point is moved to the left, to the right of the first digit
If the value is <10 ((the power of 10 is -), the decimal point is moved to the right, to the right of the first digit
I certainly didn't count the details of the number of zeros listed, but only saw the answer choices.
And the right ones are: 6.022 x 10²³
Answer:
The answer is D! 100%!
Explanation:
999 Juice Wrld Told Me So, and the internet never lies.
What kind of information does this map show?
O A. The natural resources found in different areas
O B. The elevation of Earth's surface features
O C. The roads that connect different cities
O D. The shapes of different landforms
SURMA
The half-life of plutonium-238 is 87.7 years.
What percentage of the atoms in a sample of plutonium-238 will remain radioactive after 263.1 years?
%
What percentage of the atoms in the same sample of plutonium-238 will have changed to another isotope after 263.1 years?
%
Answer:
263.1 is exactly three half-life, so the remaining portion is (1/2 x 1/2 x 1/2) of the original sample. That's 1/8 which is 12.5%
Answer:
12.5 87.5
Explanation:
What is the half life if 500 grams decays to 125 grams in 25years?
with steps pls
Answer: The half life of the sample is 60.26 years.
Explanation:
All radioactive decay reactions follow first order reaction.
The formula used to calculate the rate constant for a first order reaction follows:
[tex]k=\frac{2.303}{t}\log \frac{a}{(a-x)}[/tex]
where,
k = rate constant = ?
t = time period = 25 years
a = initial concentration of the reactant = 500 g
a - x = concentration of reactant left after time 't' = (500 - 125) = 375 g
Putting values in above equation, we get:
[tex]k=\frac{2.303}{25yrs}\log \frac{500g}{375g}\\\\k=0.0115yr^{-1}[/tex]
Now, to calculate the half life period of the reaction, we use the equation:
[tex]t_{1/2}=\frac{0.693}{k}[/tex]
where,
[tex]t_{1/2}[/tex] = half life period of the reaction = ?
k = rate constant = [tex]0.0115yr^{-1}[/tex]
Putting values in above equation, we get:
[tex]t_{1/2}=\frac{0.693}{0.0115yr^{-1}}\\\\t_{1/2}=60.26yrs[/tex]
Hence, the half life of the sample is 60.26 years.
What does electronegativity have to do with polarity?
Answer:
Electronegativity is the measure of the ability of an atom to attract electrons to itself. So, higher electronegativity helps atoms take more control over shared electrons creating partial negative regions and partial positive regions which result in dipoles that cause polarity.
Explanation:
(pls mark me brainliest)
Answer:Electronegativity is the measure of the ability of an atom to attract electrons to itself. ... So, higher electronegativity helps atoms take more control over shared electrons creating partial negative regions and partial positive regions which result in dipoles that cause polarity.
Explanation:hope this helps and if im wrong im sorry :)
two liquids are combined and a gas is released is this a chemical change?
Answer:
yes it is a chemical change
Explanation:
because first it was in liquid and turned into gas
Answer:
It's a chemical reaction
Where are earthquakes and volcanos most likely to occur?
within oceanic plates
continental boundaries
plate boundaries
hot spots
Answer:
continental plate boundaries
Explanation:
Bonus question which of these is the smallest??
Answer:
Explanation:
Atoms
Sometimes a fossil is formed as a result of the movement of an organism in soft sediment. What type of fossil is this called? bone fossil trace fossil frozen fossil petrified fossil
Answer:
The most common method of fossilization is called permineralization, or petrification.
Answer:
Trace Fossil
Explanation:
typically formed when an organism moves over the surface of soft sediment and leaves an impression of its movement behind.
1. Which of the following components does not make up rock salt? *
Answer:
In my opinion the third one is write.
Explanation:
soil.
Lowest freezing point: N2, CO, or CO2
Answer:
N2
Explanation:
CO freezing point is -337 F
CO2 freezing point is -109 F
N2 freezing point is -346F
(11....
1. Use the chart below to determine which element has the larger Zeff
value. Circle an answer for a-e:
a) Li or K b) C or O c) C or P d) C or Se e) Li or Br
Answer:
c
Explanation:
because chlorine and phosphorus
One of the main functions of the musculoskeletal system is to allow _______ of the body.
A.
reproduction
B.
movement
C.
growth
D.
maintenance
Answer:
B,Movement
Explanation:
Your musculoskeletal system includes bones, muscles, tendons, ligaments and soft tissues. They work together to support your body's weight and help you move. Injuries, disease and aging can cause pain, stiffness and other problems with movement and function.
Answer:
movement
Explanation:
you need your muscles for movement <3
In what order are redox reactions balanced?
Answer:
B
Explanation:
Answer:
b
Explanation:
a p e x :)
Step 8 measuring the volume of air near 80C ANSWERS
Temp of Gas : 82C
Height of Column of gas : 7.4
Temp of Gas : 355 K
Volume of gas : .93 cm3
Answer:
The answer is in the picture below.
Explanation:
Answer:
basically the question asked is the answer
its correct :)
Explanation:
EDGE 2023
which planets mass is nearly double that of mercury?
Answer:
earth I think like that because earth is the second planet
Car and Motorcycle engines are controlled by what chemical reaction?
Car and Motorcycle engines are controlled by a chemical reaction which is controlled by gasoline and oxygen.
What is a Chemical reaction?A chemical reaction may be defined as a process that significantly involves the chemical transformation of one set of chemical substances to another. This process involves the utilization of substances known as reactants that are transformed into other substances known as products.
The fuel in cars and motorcycles delivers the source of energy to them in order to move from one place to another. This fuel significantly contains gasoline which reacts with atmospheric oxygen and results in a small explosion which derives some sort of energy that is finally consumed by the vehicle's engine.
Apart from this, the combustion of fuel is also facilitated in the presence of oxygen which liberates extremely high amounts of carbon dioxide in the atmosphere. This reaction has also occurred in the engines of vehicles.
Therefore, car and Motorcycle engines are controlled by a chemical reaction which is controlled by gasoline and oxygen.
To learn more about Chemical reactions, refer to the link:
https://brainly.com/question/11231920
#SPJ2
Metals in general have:
a. High electrical conductivity
b. High thermal conductivity
c. High density
d. All of the above
Answer:
d. All of the above
Explanation:
With what noble gas is the cation in KNO2 isoelectronic?
Answer:
argon
For example, the K+ ion is isoelectronic with argon. Potassium has 19 electrons and 1 is in the outermost shell: a valence electron. If potassium is ionized and becomes a +1 cation, this is to say that it lost its single valence electron. This is favorable, because it gives potassium a noble gas configuration
Easy points. Chemistry question. Put the following molecules in order, from those that require the least energy to break
the carbon-carbon bond to those that require the most energy. Use the letters A, B, and C. Pls explain why
some help I’ll give brainliest
Answer: Meteoroid
Explanation:
Dwarf planets are smaller than moons
Comets are smaller than dwarf planets.
Meteoroids, Meteors, and Meteorites are broken off pieces of comets.
Meteoroids are smaller than Asteroids
What is the difference between the Lewis model and the valence-shell electron pair repulsion (VSEPR) model?
A.
Only the Lewis model shows the covalent bonds in a molecule.
B.
Only the VSEPR model can be used to explain intermolecular forces.
C.
Only the Lewis model takes into account unbonded electrons.
D.
Only the VSEPR model shows the geometric shape of a molecule.
Answer: only the VSEPR mode shows the geometric shape of a formula.