Answer:
Atomic number is 30
Explanation:
An atom consist of electron, protons and neutrons. Protons and neutrons are present with in nucleus while the electrons are present out side the nucleus.
All these three subatomic particles construct an atom. A neutral atom have equal number of proton and electron. In other words we can say that negative and positive charges are equal in magnitude and cancel the each other. For example if neutral atom has 6 protons than it must have 6 electrons. The sum of neutrons and protons is the mass number of an atom it is also called nucleon number,
while the number of protons are number of electrons is the atomic number of an atom.
For example
if an element have 12 neutron and nucleon number is 42 it means the number of protons will be = nucleon number - number of neutrons
42 - 12 = 30
Thus atomic number is 30.
Answer:
30.
Explanation:
The nucleon or mass number is the total of protons and neutrons in the nucleus.
Atomic number = nucleon number - number of neutrons in the nucleus
= 42 - 12
= 30.
Which statement about exothermic reactions is true?
The reaction container always feels cold.
The reactants have more heat energy than the products.
O Energy from an outside source is continuously being added.
More heat is given off than is put into the reaction.
Answer:
The reactants have more heat energy than the products.
Explanation:
The reactants in an exothermic reaction have higher potential heat energy than the products, this is because they release the energy as heat.
Answer:
just took test is the reactants have more heat
Explanation:
1/10 = square root of x
Answer:
x = 1/100 = 0.01
Explanation:
1/10 = √x
(1/10)² = (√x)²
1/100 = x
or x = 0.01
Define what chemical and radiant energy is
How many moles of Magnesium are present in 0.478 g of the element?
(Atomic mass: Mg-24 u)
Answer:
0.0199moles
Explanation:
The number of miles of a substance can be calculated using the formula:
Number of moles (n) = Mass (M) / Molar mass (MM)
In this question, the mass of Magnesium element (Mg) = 0.478 g while the atomic mass is 24
Therefore, number of moles of Magnesium is:
Moles = 0.478/24
Moles = 0.01992
Hence, 0.0199 moles of Magnesium are contained in 0.478 g of the element.
What is this mixture made up from? Please answer correctly !!!!!!!!!!!!! Will mark Brianliest !!!!!!!!!!!!!!!!!
Which of the following is an example of chemical weathering?
A. Splitting of rick due to expansion of water
B. Shrinkage of rock when the water is evaporated
C. Erosion due to wind-blown sand
D. Cave formation from the acid in water dissolving limestone
Answer:
d
Explanation:
disolving is a chemical like word and if a limestone cave is forming from the acid in the water thats chemical wheathering!
Answer:
Cave formation from the acid in water dissolving limestone
Explanation:
help me with this question please
Where is most of the mass of an atom located? O it is split between the nucleus and the orbits Oin the electrons Oin the nucleus Oin the orbits
Answer:
In the nucleus.
Explanation:
1
Which of the following parts of Dalton's Atomic Theory IS supported by
Thomson's and Rutherford's model?
Everything is made of atoms
Electrons are larger than atoms
Atoms are indivisible
Atoms take the form of a solid sphere
Answerfirst one
Explanation:
Calculate the volume, in liters, occupied by 0.960 mol of oxygen gas at STP.
Answer:
21.504 liters
Explanation:
Given: 0.960 mol
Volume: ?
Molar Volume at STP = 22.4 liters
0.960 mol × 22.4 L/ 1 mol =
0.960 × 22.4 L = 21.504 L
6. The concentration of a solution is : a)The amount of solvent needed to fully dissolve a solute b)The measurement of how large a mixture can get before it becomes a solution c)The measurement of how much solute can be dissolved in a liter of solvent d)The proportion of solute to solvent in a mixture
Answer:
Option c) The measurement of how much solute can be dissolved in a liter of solvent.
Explanation:
The concentration of a solution can be defined as the amount of solute in 1 litre of the solvent i.e how much of the solute that can dissolve in a litre of the solvent. Mathematically, it can be written as:
Concentration = mole of solute / Volume of solvent
Thus, the unit for the concentration is mole per litre (mol/L)
From the above illustration, we thus say that the concentration of a solution is a measure of how much solute can be dissolved in a liter of solvent.
Answer: A) Increase the amount of solute.
C) Decrease the amount of solvent.
When the temperature goes up, the volume will also go up
What is the possible reason?
Mention one real-world example?
Answer:
Yes it will
An example is ice, when it melts the volume goes up which means it occupies much more space
What is the correct order for.the three steps of the scientific method ?
write down the group numbers for carbon,oxygen,nitrogen and sulphur
Answer:
Carbon - 14
Oxygen - 16
Nitrogen - 15
Sulphur - 16
Explanation:
The question above is related to the "Periodic Table of Elements" which shows the proper arrangement of elements in a table. Every element falls on a group/family within the table. Each group has its own number, and the table has a total of 18 groups (from left to right). They are classified according to similarities in their characteristics. For example, group 1 is composed of alkali metals while group 2 is composed of alkali earth metals.
How many ATOMS of sulfur are present in 3.07 grams of sulfur hexafluoride ?
Sulfur tetra flouride formula is SF4 so there are 3.07 moles of sulfur ATOMS in there.
3. If Dr. Birdley is packing a if Dr.Birdley is packing a snowball, which of
the following properties is likely to increase?
a) mass
b) volume
c) density
d) weight
Answer:
c. density
hope this helps :)
Explanation:
Why are ions formed?
Answer:
Ions are formed when atoms lose or gain electrons in order to fulfill the octet rule and have full outer valence electron shells.
Explanation:
When they lose electrons, they become positively charged and are named cations. When they gain electrons, they are negatively charged and are named anions.
Which statement best describes the role of the nervous system? *
5 points
collects waste produced by cells and removes it from the body
O it breaks down food, absorbs nutrients, and gets rid of solid waste
O
the network of nerve cells and fibers that transmits nerve impulses between parts of
the body
O
brings oxygen into the lungs and releases carbon dioxide and water (waste materials)
from the body.
Answer:
The network of nerve cells and fibres that transmits nerve impulses between parts of the body.
Answer:
THE STATEMENT WHICH BEST FITS THE NERVOUS SYSTEM IS:THE NETWORK OF NERVE CELLS AND FIBRES THE TRANSMITS NERVES IMPULSES BETWEEN PARTS OF THE BODY.How do you solve that with fractions
Answer:
bacon
Explanation:
nator
Answer:
1.57
Explanation:
nator
how should i read chemistry ?
Answer:
CHEMIcal hiSToRY
Explanation:
can someone help and lmk if my answers are correct i don’t think they are please help i’ll give brainliest thank you
Answer:
5=C, every action has an equal or opposite reaction,
6=B, since it has less air drag and more force exerted on it
7= You're correct
Read the description of how ancient metalworkers improved their iron. Then identify the solute and solvent by filling in the blanks.
In steel, the solvent is
and the solute is
.
Answer:iron and carbon
Explanation:I took the test it’s iron and carbon
Answer:
iron and carbon
Explanation:
did the assignment on edg lmk if u need help on the assignment
1. What is the density of a strip of magnesium that occupies a volume of 8.49 mL and weighs
33.7 g.
I
Answer:
The answer is 3.97 g/mLExplanation:
The density of a substance can be found by using the formula
[tex]density = \frac{mass}{volume} \\[/tex]
From the question
mass of metal = 33.7 g
volume = 8.49 mL
So we have
[tex]density = \frac{33.7}{8.49} \\ = 3.969375736...[/tex]
We have the final answer as
3.97 g/mLHope this helps you
calculate the mass of onygen gas whose
volume is 320mL at 17 degree celsius and 2 atm Pressure
Answer:
The mass of oxygen gas is 0.96 g.
Explanation:
Given data:
Mass of oxygen gas = ?
Volume of as = 320 mL (320mL × 1L /1000 mL = 0.32 L)
Temperature of gas = 17 °C
Pressure of gas = 2 atm
Solution:
PV = nRT
P= Pressure
V = volume
n = number of moles
R = general gas constant = 0.0821 atm.L/ mol.K
T = temperature in kelvin
Now we will convert the temperature.
17+273 = 290 K
Now we will put the values in formula.
2 atm × 0.32 L = n × 0.0821 atm.L/ mol.K × 290 K
0.64 atm.L = n × 23.81 atm.L/ mol.
n = 0.64 atm.L / 23.81 atm.L/ mol.
n = 0.03 mol
Mass of oxygen:
Mass = number of moles × molar mass
Mass = 0.03 mol × 32 g/mol
Mass = 0.96 g
The mass of oxygen gas is 0.96 g.
The mass of oxygen will be "0.96 g".
Given:
Volume,
V = 320 mLor,
= 0.32 L
Temperature,
T = 17°Cor,
= 290 K
Pressure,
P = 2 atmGeneral gas constant,
R = 0.821 atm.L/mol.KAs we know the formula,
→ [tex]PV = nRT[/tex]
By substituting the values, we get
[tex]2\times 0.32=n\times 0.0821\times 290[/tex]
[tex]0.64=n\times 23.81[/tex]
[tex]n = \frac{0.64}{23.81}[/tex]
[tex]= 0.03 \ mol[/tex]
hence,
→ Mass of oxygen = [tex]Number \ of \ moles\times Molar \ mass[/tex]
= [tex]0.03\times 32[/tex]
= [tex]0.96 \ g[/tex]
Thus the above answer is right.
Learn more:
https://brainly.com/question/14049502
You are feeling ill, you go to the doctor, explain how he would use the scientific method to determine what is wrong with you
The doctor would form a hypothesis based on your symptoms. If you have a cough for instance, then s/he could hypothesize that you have a cold or flu. From that hypothesis, they would gather data in the form of measuring your vitals and so on. Using that data, they would be able to confirm the hypothesis, or reject it in form of some alternative.
a particle moves through gas at a speed of 1.5 km/m. How long will it take for the particle to go a distance of 158 m
Answer:
Particle take 0.11 min to travel 158 m distance.
Explanation:
Given data:
Speed of particle = 1.5 Km/m
Distance to cover = 158 m (158/1000 = 0.158 Km)
Time taken = ?
Solution:
Formula:
s = d/t
s = speed
d = distance
t = time
Now we will put the values in formula.
1.5 Km/m = 0.158 Km / t
t = 0.158 Km /1.5 Km/m
t = 0.11 min
Thus, particle take 0.11 min to travel 158 m distance.
What is the mass of a sample containing 3.5 moles of silicon atoms?
28 g
72g
98 g
35 g
Good scientists have what characteristics in common?
Answer:
determination or brains
Explanation:
What is the mass of an unknown object that has a volume of 20 mL and density of 3.5 g/mL?
Answer:
70
Explanation:
density=mass/volume
therefore mass = density*volume
20*3.5=70
A geologist drew a diagram illustrating a section of a boundary between two
tectonic plates. His diagram includes the geologic feature shown below.
Answer:
pls complete your question