Answer:
Option B is correct.
4
Explanation:
We know that 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 while the number of protons are number of electrons is the atomic number of an atom.
In given problem we are given with 2 neutrons of helium. We know that the atomic number of He is 2. Thus Mass number of He is,
Number of neutrons + number of proton
2 + 2 = 4
Thus, option B is correct.
Answer:
50 kg
Explanation:
Data:
Mass of bicycle = 10 kg
F = 168 N
a = 2.8 m/s²
Calculation:
F = ma Divide each side by m, Then
m = F/a
= 168/2.8
= 60 kg
m = mass of bicycle + Naoki's mass. Then
60 = 10 + Naoki's mass Subtract 10 from each side
Naoki's mass = 50 kg
The greenhouse effect is rightly called that because greenhouses allow heat to enter, but doesn't allow heat to leave, which warms plants.
On earth however, it's much bigger. Our own atmosphere acts similarly to this; it allows heat in, but doesn't allow it to leave which heats up the planet and causes global warming.
Explanation:
Tollens' reagent is prepared by using two-step process : -
Step 1:
Silver oxide is formed by mixing aqueous silver nitrate with base like sodium hydroxide. The reaction is shown below as:
Step 2
Ammonia solution is drop-wise added until all the silver oxide dissolves to form the reagent. The reaction is shown below as:
Answer:
The empirical formula is Ag2O.
The empirical formula is Ag2O.Explanation:
The empirical formula is Ag2O.Explanation:The empirical formula is the simplest whole-number ratio of atoms in a compound.
The empirical formula is Ag2O.Explanation:The empirical formula is the simplest whole-number ratio of atoms in a compound.The ratio of atoms is the same as the ratio of moles. So our job is to calculate the molar ratio of Ag to 2O.
do the steps ...
To get this into an integer ratio, we divide both numbers by the smaller value.
From this point on, I like to summarize the calculations in a table.
ElementAgMass/gXMolesXllRatiomllIntegers
—————————————————−———mAgXXXm7.96Xm0.07377Xll2.00mmm2
mlOXXXXl0.59mm0.0369Xml1mmmml1
There are 2 mol of Ag for 1 mol of O.
