Which of the following processes produces nuclei of lower mass than the reactants?
0.25 g is equivalent to..
A mixture is...
A mixture is blend of any two or more kinds of matter, as long as each maintains its own unique properties
When 5.7 m is divided by 2 s, the quotient is correctly reported as
The half-life of an isotope is the time required for the half the nuclei in a sample to
undergo radioactive decay
Applied research is carried out in order to
to solve a particular problem
A state of matter in which a material has no definite shape but has a definite volume is the ___ state.
Matter includes all of the following except
Which of the following is an intensive property of matter?
Three samples of 1.12 g, 1.8 g, and 1.52 g are mixed together. The combined mass of the three samples expressed to the correct mumber of significant figures, would be recorded as
Balance the following equations
9 Be + 4 He --> 12 C + __
4 2 6
Nitrogen monoxide and oxygen, both colorless gases, from a red-brown gas when mixed. Nitrogen monoxide and oxygen are called the
Which model of the atom explains the orbitals of electrons as waves?
the quantum model
The mass of 2.0 mol of oxygen atoms (atomic mass 16.00 amu) is
Balance the following equation:
238 U + ___ --> 239 U
Basic research is usually performed
to gain knowledge
How many quantum numbers are needed to describe the energy state of an electron in an atom?
Which concept in Dalton's atomic theory has been modified?
Atoms cannot be divied
As the atomic number increases, the number of electrons in a neutral atom
Which of the these metric units is used to measure mass?
What is the formula mass/molar of (NH4)2SO4
A spherical electron cloud surronding an atomic nucleus would best represent
an s orbital
How many half-lives are required for three-fourths of the nuclei of one isotope in a sample to decay ?
A homogeneous mixture is also called
The sequence in which energy sublevels are filled is specified by
the Aufbau principle
Which of the following lists ranks nuclear radiation from most massive to least massive?
alpha, beta, and gamma
The product of 13 cm and 5.7 cm is correctly reported as
How many atoms of flourine are present in a molecule of carbon tetraflouridem CF4?
The SI base units for length and time are
meter and second
Which of the following particles has the same mass as an electron but a positive charge and is sometimes emitted from the nucleus during radioactive decay?
The horizontal rows on the periodic table are called
Using a metric ruler with 1 mm divisions, the sides of a rectangular piece of plywood were measure as 3.54 cm and 4.85 cm, which corresponds to an area of 17.1690 cm2. Which of these shows the area expressed
If i inch equals 2.54 cm, how many centimeters equal 1 yard?
The number of significant figures in the measurement 2010 cm is
The density of pure diamond is 3.5 g/cm3. What is the volume of a diamond with a mass of 0.25 g?
The electron notation for aluminum (atomic number 13) is
1s2 2s2 2p6 3s2 3p1
All of the following describe the Heisenberg uncertainity prinicple except
it helps to locate an electron in an atom
Which of these symbols reprsents a unit of volume?
How many electrons can occupy the s orbitals at each energy level?
two, if they have opposite spins
A compund is
a substance, made of two or more atoms that are chemically bonded, that can be broken down into simpler, stable substances
If electromagnetic radiation A has a lower frequency than electromagnetic radiation B, then compared to B, the wavelength of A is
The average atomic mass of an element is the average of the atomic masses of its
naturally occurring isotopes
The average distance between the Earth and the moon is 386 000 km. Expressed in scientific notation, this distance is written as
3.86 x 10^5 km
The SI base unit for the time is the
To determine the molar mass of an element, one must know the element's
average atomic mass
The number of atoms in 1 mol of carbon is
6.022 x 10^23
The mass of a sample containing 3.5 mol of silicon atoms (atomic mass 28.0855 amu) is approximately
A line spectrum is produced when an electron moves from one energy level
to a lower energy level
If electrons in an atom have the lowest possible energies, the atom is in the
The number of atoms in a mole of any pure substance is called
The relationship between the mass m of a material, its volume V, and its density D is
D = m/V
A solid substance os
a;ways the same shape regardless of its container
Which of the following is an example of a homogeneous mixture
The dimensions of a rectangular solid are measured to be 1.27 cm, 1.3 cm, and 2.5 cm. Tje volume should be
The vertical columns on the periodic table are called
If 63.5 g of cooper (Cu) combine with 16 g of oxygen (O) to form the compound CuO, how many grams of oxygen will be meeded to combine with the same amount of cooper to form the compound CuO2
According to Bohr, electrons cannot reside at __ in the figure below
What is 1.245 633 501 x 10^8 rounded to four significant figures
1.246 x 10^8
In a chemical reaction
the mass of the reactants equals the mass of the products
How are elements artificially transmuted?
Stable nuclei are bombarded with charged and uncharged particles
A measure of the quantity of matter is
Two variables are inversely proportional if their __ has a constant value
The charge due to the electroms of a neutral atom
balances the change on the nucleus