Answer:
20 electrons
A neutral atom with atomic number 20 will have 20 electrons.
The atomic number is, by definiton, the number of protons in an atom's nucleus but for a neutral atom it's also equal to the number of electrons. Each element has a different, unique number of protons that determines its identity.
Explanation:
NaH(s)+ H2O (l)=>NaOH(aq)+H2(g)
You want to calculate the mass of NaH, I assume. Otherwise, the question isn't clear. It simply says calculate the mass(??)
So, calculate the moles of H2 gas that satisfy the conditions of 982 ml at 28ºC and 765 torr. But you must subtract the vapor pressure of water at 28º to get the actual pressure of the H2 gas. So, the actual conditions are 982 ml (0.982 L) and 301 K and 765-28 = 737 torr.
PV = nRT
n = PV/RT = (737 torr)(0.982 L)/(62.4 L-torr/Kmol)(301 K)
n = 0.0385 moles H2
moles NaH needed = 0.0385 moles H2 x 1 mole NaH/mole H2 = 0.0385 moles NaH required
mass of NaH needed = 0.0385 moles x 24 g/mole = 0.925 g NaH
Brainliest Please :)
<h3>
Answer:</h3>
0.012 dekameters (dkm)
<h3>
Explanation:</h3>
<u>We are given;</u>
Required to identify the measurements that is not equivalent to 120 cm.
- Centimeters are units that are used to measure length together with other units such as kilometers(km), meters (m), millimeters (mm), dekameters (dkm), etc.
- These units can be inter-converted to one another using suitable conversion factors.
- To do this, we are going to have a table showing the suitable conversion factor from one unit to another.
Kilometer (km)
10
Decimeter (Dm)
10
Hectometer (Hm)\
10
Meter (m)
10
Dekameter (dkm)
10
Centimeter (cm)
10
Millimeter (mm)
Therefore;
To convert cm to km
Conversion factor is 10^5 cm/km
Thus;
120 cm = 120 cm ÷ 10^5 cm/km
= 0.0012 km
To convert cm to dkm
Conversion factor is 10 cm/dkm
Therefore,
120 cm = 120 cm ÷ 10 cm/dkm
= 12 dkm
To convert cm to m
The suitable conversion factor is 10^2 cm/m
Thus,
120 cm = 120 cm ÷ 10^2 cm/m
= 1.2 m
To convert cm to mm
Suitable conversion factor is 10 mm/cm
Therefore;
120 cm = 120 cm × 10 mm/cm
= 1200 mm
Therefore, the measurement that is not equal to 120 cm is 0.012 dkm
Its A. because it measures the rate of the decay of the isotope
Answer:
It cant
Explanation:
It can not tell because the size of a human and an object to 2 different sizes. Therefor since they are 2 different sizes they can handle different amounts of temperature.
