The mass number is the summation of number of proton and neutron present in a nucleus of an atom. For the neutral atom the number of positive charge (number of proton) must be equal to the number of electrons. The number of electrons present in an atom is the atomic number of the atom. The standard way to express the mass number (a) and atomic number (m) of a atom (say X) is 
. Now for silicon number of electron or atomic number is 14. And the mass number (a) given 29. Thus the expression nucleus of silicon will be 
Answer:
29260J
Explanation:
Given parameters:
Mass of water sample = 100g
Initial temperature = 30°C
Final temperature = 100°C
Unknown:
Energy required for the temperature change = ?
Solution:
The amount of heat required for this temperature change can be derived from the expression below;
H = m c (ΔT)
H is the amount of heat energy
m is the mass
c is the specific heat capacity of water = 4.18J/g°C
ΔT is the change in temperature
Now insert the parameters and solve;
H = 100 x 4.18 x (100 - 30)
H = 100 x 4.18 x 70 = 29260J
Answer:
Barium and sulpher are the elements that forms barium sulphide .
And its molecular fomula is BaS.
Explanation:
Answer:
Genes
Explanation:
The genes are the basic unit of hereditary which are a part of chromosomes that are passed from parents to their offspring.
Genes are responsible for the propagation of hereditary features. They are usually located on the chromosome.
Genes are made up of protein molecules.
Each parent passes down a copy of their gene which are inherited by the offspring and they determine a character state.
They generally make up the genotype.
Answer:
d = 0.992 g/L
Explanation:
Data Given:
Pressure of nitric oxide (NO) = 0.866 atm
Temperature of a gas = 46.2° C
Convert the temperature to kelvin = 46.2° C + 273
temperature in kelvin = 319.2 K
density of nitric oxide (NO) = ?
Solution:
Density of a gas can be calculated by
d = PM /RT
Where
d = density
P = Pressure
M = molar mass of gas
R = ideal gas constant = 0.0821 L atm mol⁻¹ K⁻¹
T = temperature
So,
Molar mass of NO = 30 g/mol
Put values in the formula:
d = PM /RT
d = 0.866 atm × 30 g/mol / 0.0821 L atm mol⁻¹ K⁻¹ × 319.2 K
d = 25.98 atm. g/mol / 26.2 L atm mol⁻¹
d = 0.992 g/L
